BIOL FOR SCI MAJ II
BIOL FOR SCI MAJ II BIOL 1202
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Date Created: 10/13/15
0 Ch 22 I Monday January 14 2008 1013 AM 0 Ch 22 Descent with Modification A Darwinian View of Life The theory of evolution is a valid scientific theory supported by evidence What is Evolution and Adaptation 0 Two main ideas of evolution I Change over time of the genetic composition of a population I Decent of modern organisms with modification from preexisting organisms o All organisms derived from a common ancestor o Evolutionary adaptation I Accumulation of inherited characteristics that enhance organisms ability to survive in specific environments 0 Traits that help organisms survive and reproduce that have an effect on the frequency of genes in future generations 0 Evolution in a Historical Context 0 Figure 222 o Catastrophism Gradualism and Uniformitarianism I Curvier catastrophism o Catastrophes caused extinct species and formation of strata layers of sedimentary rock stacked up over long periods of time o More biblical interpretation Noah s Flood 0 Where were fossils of species that are around today I Hutton and Lyell gradualism and uniformitarianism 0 Slow natural forces wind water earthquake volcanoes caused stratification and erosion of rock over time Observations of geological formation rates processes occur Earth at least millions of years ago 0 Pre Darwinian Theory of Evolution I Lamarck Inheritance of acquired characteristics 0 Bodies of living organisms are modified through the use or disuse of parts 0 These modifications are inherited by offspring 0 ie Giraffes stretched necks to reach trees which gave them longer neck and legs over time and offspring gained long features 0 This idea turned out to be wrong 0 What you do in your lifetime won t necessarily influence offspring 0 Muscle builder won t necessarily have large muscles Jewish boys aren t born without foreskin even though they have been circumcis2ed for centuries 0 Evolution by Natural Selection 0 Darwin and Wallace developed the theory independently I First credible account of how organisms change over time 0 Darwin voyage ofthe Beagle I Extensive study of finches on Galapagos islands I Explained how organisms could change over time 0 Wallace naturalist in Indonesia I Wrote up natural selection ideas and sent them to Darwin I Both accounts were combined and presented 0 Darwin s Focus on Adaptation 0 Different environmental adaptations I Insect eaters long slender beaks I Seed eaters large curved beaks I Cactus eaters small pointed beaks 0 Thought they were similar species that came from a common ancestor 0 As they began to exploit different habitats they changed through time and evolved with different environment 0 Decent with Modification 0 They were likely birds from a single common ancestor I Took on different ecological niches I Took on different anatomical form that made them more adapted to their environments 0 Similar anatomical features of elephants in Africa and Asia because they descended from a common ancestor 0 Natural Selection 0 The unequal survival and reproduction of organisms due to environmental forces resulting in the preservation offavorable adaptation I Organisms that have characteristics that help them to survive and reproduce pass along their genes to the future generation and have a disproportionate effect on the population I Favorable traits are passed on and have a larger impact on the population than unfavorable ones Process quotselectsquot from what is available in the gene pool New characteristics are not created on demand 0 O I If traits do not occur through mutation or already exist they will not come in effect 0 Mechanism behind Natural Selection I Figure on pg 444 I Organisms have the capacity for producing more offspring than can survive at one time 0 Only small percentages of offspring survive I The resources to support the organisms are finite o Aren t enough for all offspring to survive I Population sizes are relatively constantstable over time I Must be competition for survival and reproduction with these selective pressures I Competition and variable in structurebehavior cause natural selection I Ones with favorable traits fittest survive and those genetic traits are inherited by the next generation eventually changing the gene frequencies in a population causing evolution O Thinkabout the 100m dash track and field competition How can we change this race to reflect the process of natural selection I Hurdles I Last one to the finish is out I Run uphill I Tiger chasing I Reproduction winners must be able to reproduce 0 Artificial Selection 0 Selective breeding of organisms to encourage the occurrence of desirable traits I Humans make the selection the agents of selection I Larger fruits high quality meatmilk livestock o Analogous similar to natural selection I Instead of the fittest and most reproductive survive those humans select survive 0 Figure 2210 c Darwin s Theory Explains a Wide Variety of Observations 0 Examples of Natural Selection I Reznick and Endley transplanted guppies into different ponds with different predators o Killifish preyed on small guppies gt Guppies larger at sexual maturity o Pikecichlis preyed on large guppies gt Smaller at sexual maturity 0 Put guppies from Pikecichlis pond into the Killifish environment and saw that those guppies changed their maturity size became larger 0 Selective pressure resulting in an observable evolutionary change I HIV Resistance 0 Figure 2213 c Brought about by use of drug to fight these infections 0 3TC Drug that stops the reproduction of HIV 0 Some of the viral particles that are resistant to the drug and very quickly the selective pressure causes an influx of resistant HIV 0 Within a few weeks of treatment with the drug 3TC a patients HIV population consists entirely of 3TC resistant viruses How can this best be explained o A few drug resistant viruses were present at the start of treatment and natural selection increased the frequency Fossil Records Flg2215 Show change in organism over time Change in types of organism 0 Past organism differ from present day organism 0 Many become extinct o Whales OOO O Evolved from land dwelling animals that took sea and lost legs 0 Fig 2216 c Homologous and Analogous Structures 0 Homologous may differ in function but has similar underlying anatomy Reason Species share a common ancestor Mammalian forelimbs 0 Same bone structure in human cat whale and bat forelimb but used for different purposes Vertebrate embryos o Chick and human embryo have similar features but the develop into different traits o All vertebrates share similar developmental genes 0 Differences arise by some genes being expressed differently Biochemistry and Molecular Biology 0 DNA is universal genetic material 0 All life forms use approximately the same 20 amino acids to make proteins 0 All use ATP as the primary form of cellular energy 0 All use RNA and ribosomes to make proteins Molecules 0 Differences that arise in characteristics have a genetic cause 0 Diverged lineages independently accumulate mutations c Number of differences is related to the amount of time since divergence c Figure 2216 Percent of amino acids that are identical to the amino acids in a human hemoglobin polypeptide 0 Human 100 Monkey 99 Mouse 87 Chicken 69 Frog 54 Fish 14 o Analogous similar function and superficially similar appearance but different underlying anatomy convergent evolution Organisms derive from different ancestors but live in similar habitats so develop similar features 0 Biogeography Geographic distribution of species 0 Darwin observation 0 Closely related species tend to be found in the same region Convergent evolution 0 Organisms evolve from different ancestors but living in similar environments They evolve analogous structures Figure 2217 Flying squirrels are similar in Australia and in North America 0 Derive from different relatives but have similar analogous structures because they live in similar environments 0 Examples I Forelimb of dragon fly vs seal not homologous not analogous not similar in anatomy or purpose I Forelimb of bird vs penguin homologous same anatomy not analogous used for different purposes I Forelimb of penguin vs seal homologous same anatomy analogous both use forelimbs to swim 0 Questions 0 Which ofthe following pairs of structure is least likely to represent homology I The wings of a bat and the forelimbs of a human I The legs ofa bird and those of an insect legs ofa bird are supported by endoskeleton while the legs of an insect are supported by exoskeleton I The hemoglobin ofa baboon and that ofa gorilla I The mitochondrial ofa plant and that of an animal 0 Ch 23 Friday January 1 20113 93940 ANT Ch 23 The Evolution ofPopulations The Smallest Unit of Evolution 0 One common misconception about evolution is that individual organisms evolve during their lifetime 0 Evolutionary processes natural selection acts on individuals but populations evolve Concept 231 Population genetics provides a foundation for studying evolution 0 Microevolution change in the genetic makeup of a population from one generation to the next 0 Population genetics the study of how populations change genetically over time I Time is measured in generations Population 0 A localized group of individuals that are capable of interbreeding and producing fertile offspring Figure 233 Mendelian Inheritance o Segregation of genes during meiosis ensures that genetic variation is preserved from one generation to the next Figure 234 HardyWeinberg Equilibrium o Describes a population that is not evolving ie allele frequencies don t change 0 Five assumptions behind equilibrium I No mutations I Large population size I No gene ow I No natural selection I Random mating o Allele and Genotype Frequencies I HW equations p22pqq21 I Allele frequencies 0 p frequency of allele 1 q frequency of allele 2 I Genotype frequencies 0 p2 frequency of homozygous dominant o q2 frequency of homozygous recessive o Conn o Populat o O o 2pq frequency of heterozygotes Figure 235 ion Genetics and Human Health HW equation can be used to estimate the of the human population carrying the allele for an inherited disease PKU is a recessive genetic disorder Frequency of homozygote with this disorder is q2 00001 What is the frequency of the dominant and recessive alleles p q q sq1t00001 001 pq1sop099 The frequency of carriers heterozygous people who do not have PKU is 2pq 2001099 00198 Mutation and Sexual Recombination produce the variation that makes evolution possible Mutation Changes in nucleotide sequence of DNA source of new alleles and genes Without mutation there would be no variation Point mutation change in one nucleotide base in a gene Doesn39t always change the amino acid some do change and can cause detrimental disorders Chromosomal mutation delete disrupt or rearrange many loci on a chromosome Cause changes in how and when proteins are expressed often lead to detrimental disorders Gene duplications duplication of whole segments of a chromosomes ead to the creation of many copies of a particular genes works well with genes that needs to be expressed on a large leve Original copy of gene can continue to function but the copy is free to change into a form of protein I Mutation rate average 1 in ever 100000 genes per generation 0 I 0 Genetic drift an 0 Sexual Recombination In sexually reproducing organisms sexual recombination produces most of the variability in each generation 0 Crossing over during prophase I 39 t durin 1 d gene flow can alter a population s genetic composition concept 223 A I Genetic Drift Statistically the smaller a sample the greater the change of deviation from a predicted result With small population sized allele frequencies can uctuate unpredictably from one generation to the next Large populations see smaller changes Tends to reduce genetic variation the effect of small population on gene frequencies Figure 23 7 The Bottleneck Effect Genetic drift resulting from the reduction of a population 0 Some event causes the population to decrease drastically The surviving population is no longer genetically representative of the original population 0 Chance events decides which organisms survive Causes a decrease in genetic variability 0 Only genes from the few surviving individuals are passed on to future generations 0 Figure 238 The Founder Effect 0 Gene Flow Genetic drift that occurs when a few individuals become isolated from a larger population The new population s gene pool is not re ective of the source population Pennsylvania Amish Amish immigrated from Germany to souther Pennsylvania Isolated community do not interbreed with surrounding population Genes brought over stay within the population High incidence of Ellis van Carvel syndrome Polydactyl in ngers and toes Very rare in the German population of Amish but very common in Pennsylvania Amish 10 increase 000000 0 Out of the 10 migrating families that migrated one couple was a carrier of the syndrome which increased the occurrence of the syndrome I Gene additions to or subtractions from a population resulting from the movement of fertile individuals or gametes between 2 or more populations I Migration among populations I Tends to reduce variation among populations over time different populations become more uniform genetically Without gene ow you would see a greater genetic variation between the different populations 0 Natural selection is the primary mechanism of adaptive evolution concept 234 0 Natural selection the differential success in the reproduction of different phenotypes resulting from their interactions with the environment I Favorable phenotypes caused by limited resources and competition 0 Results in certain alleles being passed to the next generation in greater proportions I Organisms with more advantageous traits will survive longer and have more offspring o Accumulates and maintains favorable genotypes 0 Variation within a Population 0 Discrete characters classi ed on an eitheror basis I Usually determined by an individual gene I IE ower color in pea plants 0 Quantitative characters vary along a continuum within a population I Usually determined by several genes I IE height weights 0 Evolutionary Fitness 0 Fitness the contribution an individual makes to the gene pool of the next generation relative to the contributions of other individua s o 0 Tom Dick 0 Harry 0 Size 0 6 3quot 5 10 185 0 5 5 125 2001bs lbs lbs 0 Children o 5 3 o 3 l o Grandchildren o 2 4 o 8 l 0 Comments 0 Don Athlete o Nerd Iuan 0 Out of Tom Dick and Harry who had the greatest tness IHa rry o Directional Disruptive and Stabilizing Selection 0 Figure 2312 Directional Selection switch in the 39 39 t 39 favors39 quot quot 39 atone extreme or the other causing a shift toward the extreme Disruptive selection favors both extremes of phenotypes causing a dip in intermediate phenotypes Stabilizing selection increase in the number of average intermediate phenotypes causes decrease in extreme phenotypes A population of seed cracker nches has small and largebilled birds specialized in soft and hard seeds respectively If climatic change resulted in all seeds becoming hard what type of selection would then operate on the nch population Directional Selection 0 The Preservation of Genetic Variation Various mechanisms help to preserve genetic variation in a population Diploidy maintains genetic variation in the form of hidden recessive alleles O O ature of sexually reproducing organisms Recessive alleles are maintained by heterozygotes who have dominant phenotype o Balancing selection occurs when natural selection maintains stable frequencies of two or more phenotypic forms in a population Frequency dependent selection Allele give disadvantage in some cases but advantage in others Heterozygous J t g 39 quot 39 39 39 at are at a particular locus have a greater fitness than individuals that are homozygous for the dominant or recessive allele 0 Maintains the frequency of both alleles within the population 0 Sicklecell recessive allele causes mutations in hemoglobin but also confers malaria resistance 0 Homozygous recessive have sickle cell anemia and don t get enough oxygen typically fatal 0 Heterozygotes are less susceptible to malaria originated in Africa where malaria was prevalent I Live and reproduce at a greater rate 0 Homozygous dominant usually die of malaria 0 Sexual Selection Type of selection that favors a trait giving an individual a competitive edge in attracting or keeping a mate 0 O O Nonrandom mating factor of HW equilibrium Can result in sexual dimorphism males and females have slightly different traits o Intrasexual selection direct competition among individuals of one sex for mates of the opposite sex Usually competition sometimes physical between males for access to a female Seen in dominant hierarchies Intersexual selection individuals of one sex usually females are choose in selecting their mates from individuals of the other sex 0 Ch 24 Ex Peahen has very drab colored feathers with short tail feathers Peacocks have bright colorful plumage and elaborate tailfeather displays to attract the peahen Friday January 25 20113 958A1Mf 39 Ch 24 The Origin of Species Speciation O Anagenesis accumulation of heritable changes altering the characteristics of a species I One species gt one different species 0 Cladogenesis new species arise from a population being isolated from the parent species I One species gt two different species 0 Figure 242 o The biological species concept emphasizes reproductive isolation concept 241 0 Species Latin for quotkindquot or quotappearancequot I Use to use what a species looked like to determine if they were of different or ofthe same species I But just because two organisms look similar does not mean they are the same species 0 EX Two nearly identical dragon ies are different species and two dogs one very small and one very large are the same species 0 The Biological Species Concept I De nes a species as a population or group of populations whose members have the potential to interbreed in nature and produce viable fertile offspring c There are instances in zoos where tigers and lions can be bred together but will never really encounter each other in nature so they are not the same species I Cannot be applied to o Asexual organisms o Binary fission prokaryotes protists 0 Plants 0 Fossils 0 Can t determine if those organisms interbred o Organisms about which little is known regarding their reproduction o Speciation Depends on Two Things 0 Reproductive isolation I Populations are seperated by some barrier so there is no gene ow between all populations Any changes that occur on one side of the barrier will not carry over to the other side Enough changes can occur between populations where the populations will eventually not breed when brought back together in contact therefore a new species is formed I The existence of biological factors that impeded members of two species from producing viable fertile offspring o Prezygotic barriers prevents sperm from fertilizing egg 0 Impedes mating between species or hinders the fertilization of ova if members of different species attempt to mate Habitat Isolation two species may occupy the same area but tend to live in different habitats within that same area Temporal Isolation the breeding time time of day seasonal or years of one species is different than that of the other a n O O o Behavioral Isolation many animal species have very speci c courtship behaviors prior to mating if two individuals of a different species encounter each other the incorrect courtship will cause rejection 0 Mechanical Isolation the reproductive structure of the different species may not be compatible so they are unable to reproduce Gametic Isolation sperm is unable to fertilize the egg the receptor proteins on the membrane of the egg are not compatible with the eggs so the egg will not accept the sperm I Question Is gametic isolation a prezygotic or postzygotic isolating mechanismPrezygotic o Postzygotic barriers fertilization does occur but for some other reason the fertilized egg does not develop into a viable offsprin 0 Reduced hybrid viability hybrid offspring are usually born very weak and don39t survive to sexual maturity 0 Reduced hybrid fertility hybrid offspring are sterile cannot produce viable gametes 0 Hybrid breakdown hybrid is viable and fertile but the hybrid becomes weaker and weaker over generations and doesn t survive after a few generations Two species of pine are found in the same habitat but release pollen at different times during the year This is what type of isolation 0 Temporal During a study of two closely related animals it did not appear as though they were reproductively isolated until the possibility that their different ecological niches could result in isolation was noted 0 Habitat I Genetic divergence Which of the following is not considered a requirement for Speciation to occur High levels of gene flow among populations must occur Concept 242 Speciation can take place with or without geographic separation o Speciation can occur in two ways Fig 245 39 Allopatric Speciation geographic isolation so there is no gene ow between the population 0 quotOther Countryquot 0 Gene ow is interrupted or reduced when a population is divided into two or more geographically isolated subpopulations Occurs when two populations are separated from one another by some geographic barrier Single species homogeneous habitat gt Geographic barrier isolated populations gt Genetic drift mutation natural selection cause genetic divergence gt Barrier removes population mix but don t interbreed Examples Volcanic islands Hawaii species come from California and become isolated on either side of the Isthmus of Panama Fig 247 39 Sympatric Speciation isolation mechanisms aren39t geographic some other isolating mechanisms habitat or behavioral O Adaptive Radiation quotSame Countryquot Speciation that takes place in geographically overlapping populations Not separated from one about by a geographic barrier but process of genetic divergence still occurs in populations Single species homogeneous habitat gt Environment change two habitats populations isolated by habitat gt Environmental pressure to adapts genetic divergence gt Suf cient divergence reproductive isolation Example Cichlid sh nonrandom mating due to sexual selection Polyploidy O O O O O The presence of extra sets of chromosomes in cells due to accidents during meiosis Has caused sympatric speciation in many plant species Autopolyploidy individual has more than two chromosome sets all derived from a single species I Figure 248 During cell replication cell division fails to occur causing an extra set of chromosomes in the mother cell and consequent daughter cells are diploid instead of haploid Allopolyploidy species with multiple sets of chromosomes derived from different species I Meotic error chromosome number not reduced from 2n to n I This 2n combines with a normal n gamete giving a 3n but this does not have equal number of homologous chromosomes I Another normal n gamete combines with the 3n to make the full compliment Plant species A has a diploid of 12 Plant species B has a diploid of 16 A new species C arises as an allopolyploid from A and B The likely diploid number for species C would be I 28 I A 2nl2 B 2nl6 I B gives n8 Ahas a mistake and still has diploid of 12 giving a zygote of l28 20 I This zygote does not have a full compliment so must combine with another B gamete making it 20828 o The emergence of numerous species from a common ancestor that has colonized a new environment I Speciation occurs rapidly because there are no organisms living their previously and it become colonized rather quickly 0 The Hawaiian archipelago has many examples of adaptive radiation Macroevolutionary changes can accumulate through many speciation events Concept 243 o Macroevolution evolutionary change above the species level including the appearance of major evolutionary developments 0 Culmination of many small speciation events 0 Evolution of Complex Organs oooum I Complex structure in organisms are often derived from previously existing structures I EX Eye 0 Evolution of the Genes that Control Development I These genes control the rate timing and spatial pattern of changes in an organism s form during devlopment Allometric growth proportioning that gives a body its speci c form Differences in allometric growth between closely related species can lead to large differences in adults Ch 25 W iesclay January 30 low 93943 NV Ch 25 Phylogeny and Systematics Phylogeny the evolutionary history of a species or group of species Systematics an analytical approach to understanding the diversity and relationships of organisms o Morphological biochemical and molecular comparisons used to infer relationships Morphological and Molecular Homo lo gies O OO O O Phylogenetic history can be inferred from certain morphological and molecular similarities among organisms Generally similar morphology and similar DNA sequences closely related species But beware of analogous structure or molecular sequences aka homoplasies I Similarity may be due to convergent evolution analogy not shared ancestry homology Is the similarity between the Australian mole and North American mole due to homology I No they are similar due to convergent evolution I Mammals in Australia are marsupial North American mammals are placental I Share a common habitat so have similar structures burrowing underground Evaluating Molecular Homologies I Homologous DNA sequences Figure 256 o Mutational changes cause a different in DNA but have very similar sequences if mutations are removed I Molecular homoplasy analogous sequences Figure 257 0 Two nonhomologous sequences 0 Because there are only 4 base pairs it is likely to get matching sequences sporadically I A researcher compared the nucleotide sequences of a homologous gene from ve different species of mammals The sequence homology between each species39 version of the gene and the human gene are presented as a percentage of similarity in the table below 0 Species 0 Percent Similarity o Chimp o 997 o Orangutan o 986 o Rhesus o 969 monkey 0 Rabbit o 937 o What conclusions can validly be drawn from this data I Humans shared a most recent common ancestor with chimps o Phylogenetic systematics connects classification with evolutionary history Concept 252 0 Taxonomy the ordered division of organisms into categories based on a set of characteristics used to assess similarities and differences 0 Binomial Nomenclature I The two part format of scienti c name of an organism I Created by Carolus Linnaeus I The binomial name consists of o Genus and species 0 These are always written in a different font italics o Genus is always capitalized species is always lowercase 0 Ex Homo sapiens o HierarchicalClassi cation I Linnaeus also introduces the system for grouping species in increasingly broad categories I King Philip Chooses inyFried Greasy quid gt Kingdom phylum class order family genus species 0 Linking Classi cation and Phylogeny I Systematists depict evolutionary relationships in branching phylogenetic trees I Each branch point node represents the divergence of two species I Deeper branch point represent greater amounts of divergence I Lines represent lineages o Phylogenetic systematics informs the construction of phylogenetic trees based on shared characteristics 0 Cladistics I Cladogram a diagram depicting patterns of shared characteristics among species I Clade within a cladogram a group of species that includes an ancestral species and all of its descendents o Monophyletic Grouping I Made up of an ancestral species and all of its descendants I Only monophyletic groups qualify as legitimate taxa in cladistics o Paraphyletic Grouping I Consists of an ancestor and some but not all of that ancestor s descendants o Polyphyletic Groupin I Grouping that lacks the common ancestor of the species in the group 0 Ch 26 a trayquot y Feanary 1 El 108 a 93944 AlVl 0 Ch 26 The Tree of Life All 39 quot into Biological Diversity 0 Early Earth 0 Earth is about 46 billion years old I Radiometric dating of meteorites and mood rocks 0 Life arose about 28 byago I Chemical traces in rocks 38 by ago I Fossil bacteria in rocks 35 by ago 0 No spontaneous generation now but must have happened then Conditions of Early Earth 0 Atmosphere I C02 CH4 NH3 st H20 0 Abundant energy to drive reactions I Frequent storms with much lightening I Frequent volcano eruptions I Frequent meteor impacts I UV light from the sun How to Assemble a Living Thing from nonliving things Testable Hypothesis explaining the origins of life 0 Abiotic synthesis of small organic molecules nucleotides amino acids 0 Joining these molecules into polymers long chains of nucleotides amino acids 0 Packing these molecules intro quotprotiobiontsquot have a membrane to separate from environment 0 The origin of selfreplicating molecules Miller amp Urey Experiments 0 Electric spark simulates lightening o Gases of primeval atmosphere abiotic conditions 0 Organic molecules appear only after a few days 0 Figure 263 Alternative Hypotheses 0 First organic compounds may have been synthesized near hydrothermal vents volcanic hot springs at bottom of the ocean o Extraterrestrial origin Creation of Life from Abiotic materials 0 Abiotic Synthesis of Polymers I Small organic molecules polymerize when they are concentrated on hot sand or clay o Protobionts I Aggregates of abiotically produced molecules surrounded by a membrane I Liposomes pockets with membrane can form when lipids or other organic molecules are added to water I Figure 264 o The Chicken or the Egg DNA or Protein rst I Now 0 DNA gt RNA gt Protein 0 Need proteins to syntthesize more DNA I Then Earliest cells used RNA to store info Ribozymes to catalyze reactions 0 Found to catalyze many different reactions including I Selfsplicing I Making complementary copies of shortstretches of RNA 0 The Fossil Record Chronicles Life on Earth Concept 262 0 Dating Rocks and Fossils I Sedimentary strata reveal the relative ages of fossils o Fossils near surface more recent 0 Deeper fossils more ancient I Radiometric Dating 0 Can determine absolute ages of fossils 0 Potassium 40 40 K naturally decays to Argon 40 40Ar I When a certain rock formed it contained 12 mg 40 K The rock now contains 3 mg 40Ar The halflife of40 K is 13 billion years How old is the rock 0 26 BY 0 As prokaryotes evolved they exploited and changed young Earth Concept 263 0 First organisms were anaerobic metabolize without oxygen prokaryotes I Bacteria amp Achaea I Fed on accumulated organic molecules heterotrophic o Oxygenic photosynthetic bacteria evolved 35 BYA I C02 HzO gt Food 02 0 Oxygen accumulated in the atmosphere 27 BYA o Stromatolites bacteria form mats over the surface of a shallow water body and forms a sticky film where bacteria gets covered by sediment so must grow over them to photosynthesize happens over and over forming stromatolites o Eukaryotic cells arose from symbioses and genetic exchange between prokaryotes Concept 264 o Eukaryotes cell membrane nucleus membrane bound organelles o How did complex eukaryotic cells evolve from much simplest prokaryotic cells 0 The First Eukaryotes I Oldest fossils of eukaryotic cells are 21 BYA I Endosymbiotic Theory 0 Mitochondria and plastic were formerly small prokaryotes living within larger hosts cell 0 Were possibly undigested prey or internal parasite or mutualists 0 Ch 27 Friday Febmary HS 3108 9 I Ch 27 Prokaryotes Structural functional and genetic adaptations contribute to prokaryotic success Concept 271 o Prokaryotes are unicellular I Some colonial forms 0 Range in size from 15 micrometers I Some large as 750 micrometers exception 0 No membranebound organelles ooum 0 Circular chromosomes 0 Prokaryotic Domains I Comparison of traits found in the two prokaryotic domains Bacteria and Archaea Table 272 I Some traits are similar prokaryotic traits but some are different 0 Prokaryotic cells have a variety of shapes I The three most common are spheres cocci rods bacilli and spirals spirilli Figure 273 o CellSurface Structures I Cell Wall o Maintains cell shape provides physical protection prevents cell from bursting in a hypotonic environment Composed of peptidoglycan May also have an outer phospholipid membrane Grampositive cell wall outside of cell membrane 0 Appear purple when stained Gramnegative cell membrane and cell wall with peptidoglycan layer and outer membrane 0 Appear pink when stained 0 Figure 273 I Capsule sticky layer of polysaccharide or protein 0 May cover the cell wall of many prokaryotes 0 Protective layer I Fim briae and pilli allow prokaryotes to stick to their substrate or other individuals in a colony o Motility I Motile bacteria move by means of agella o Structurally different from eukaryotic agella 0 Long string of proteins eukaryotes are made of microtubules I In a heterogeneous environment bacteria exhibit taxis ability to move toward or away from certain stimu i 0 Positive chemotaXis moving toward a chemical stimulus 0 Negative chemotaXis moving away from the chemical stimulus 0 Internal Organization I Prokaryotes do not have membranebound organelles I Some do have specialized membranes that perform metabolic functions 0 Aerobic prokaryotes respiratory membrane 0 Photosynthetic prokaryotes thylakoid membrane 0 Figure 277 o Genome Organization I Prokaryotic chromosome circular DNA found in the nucleoid region 0 Not in a nucleus I Plasmid smaller circular DNA rings 0 Additional genes not always necessary for basic survival 0 EX Antibiotic resistant gene is on a plasmid o Reproduction I Prokaryotes reproduce quickly by binary ssion 0 Can divide every 13 hours 0 Duplication of chromosome continued growth of the cell division into two cells I Form of asexual reproduction o Produces genetically identical daughter cells I Bacterial conjugation not true reproduction 0 Transfer of genetic material between two bacteria 0 Not necessarily the same species Horizontal gene transfer 0 Plasmids are usually transmitted from donor through sex pilus o A great diversity of nutritional and metabolic adaptations have evolved in prokaryotes 0 Different types of metabolism I Phototrophs organisms that obtain energy from light I Chemotrophs organisms that obtain energy from chemicals I Autrotrophs organisms that need only the inorganic compound C02 as a carbon source for making organic molecules Heterotrophs organisms that need at least one organic compound like glucose to make other organic compounds 0 Major Nutritional Modes in Prokayotes Table 271 I Photoautrotrophs use light and CO2 I Chemoautrotrops inorganic molecules and CO2 I Photo geterotrophs light and organic molecules I Chemoheterotrophs inorganic and organic compounds 0 Metabolic Relationships to Oxygen o Prokaryotic metabolism can very with respect to oxygen availability I Obligate aerobes require oxygen to run metabolism I Facultative anaerobes can survive with or without oxygen 0 Fermentation when no 02 is present I Obligate anaerobes are poisoned by oxygen 0 Fermentation o Anaerobic respiration substances other than 02 act as electron receptors ie N0339 SO4239 Found in the bottom of lakes swamps and deep ocean waters 0 Winogradsky Column I Column lled with different sediments oxygen has a hard time diffusion down sediments I Top is aerobic water obligate aerobic bacteria live I Oxygen depletes going down the column where facultative anearobes live I No oxygen at bottom where obligate anaerobes live 0 NitrogenMetabolismFixation I Some prokaryotes can metabolize nitrogen I In nitrogen xation bacteria convert N2 nitrogen gas from the atmosphere to make NH3 ammonia I Nitrogen xing bacteria live in roots of the plants use carbohydrates from plants 0 Metabolic cooperation I Cooperation between prokaryotes allows them to use resources they could not use individually I The cynobacteriaAnabaena o Photosynthetic cells produces oxygen 0 Nitrogen xing cells heterocytes must be done in anaerobic environment so must be separated by very thick cell walls from the photosynthetic cells 0 Molecular systematics is illuminating prokaryotic phylogeny Concept 273 0 Until the late 20th Century systematists based prokaryotic taxonomy on phenotypic criteria 0 Applying molecular systematics I Has led to a phylogenetic classi cation of prokaryotes I Allows systematists to identify major new clades o A tentative phylogeny of some of the major taxa of prokaryotes based on molecular systematics is shown below Domlln mum Knrarchaenm Euyyavchaootel Cmuarchueoms Nanoamhaeotzs 0 Domain B acteria I Proteobacteria diverse group of gramnegative bacteria I Chlamy quotas I Gmmpositive bacteria Cyanobacteria photoautotrophs 0 Domain Archea I Archaeans are o en found in extreme environments classi ed by their environment I Thermophiles thrive inver hot environments hypothermal vents on ocean oor I Barophiles thrive under high pressure bottom of the ocean I live in dJIUAiL 39 methane as Waste product 0 Take carbon sources and convert to methane Halophiles live in high saline environments produce 0 Questions 0 Groupsof staphylococci look like I Clusters of grapes circular 0 An autotrophic organismrni I Engage in chemosynthesis o Chemosynthesis I Enables the synthesis or organic molecules using energy from inorganic molecules 0 Which types of bacteria can live in the presence of oxygen I Only obligate aerobes and facultative anaerobes 0 which of the following types of bacteriaWould you be most likely to nd in ver salty Water I Extreme halophiles Ch 28 Mandnys February 112002 101 A h 28 r Pro sls protists are an extremely diverse assortment ofeukaryotes an Most unicellular but some colonial and rnulticellular forms Re roduce sexually and asexually o protists are nutritionally diverse Photoautotr phs Contain chloroplasts photosynthesize Heterotrop s Absorb organic rnolecules or ingest large particles Mixotrops Combine photosynthesis and heterotrophic nutrition 0 Endosynibiosis in Eukaryotic volu ion Much protist diversity has its origin in endosyrnbiosis plastidbean39ng lineage evolved into red and green algae Both underwent secondary endosyrnbiosis Plailld J k V c Dinnllagullams 1 w 39 Aplnamplexzns mm nuns l Cyunubanlevlum l 7 Y up 1 lendusymblosrlsi I smmancpiles ac quotMinnie more 39 P 3 Euqlsnlds ll Green algae 0 Eu glen ozoans have agella with a unique intemal structure 0 i i i r and parasites on cl rim Crystalline rod 0 Ring of microtubules o anetoplastids I Single large mitochondrion containing an organized mass of DNA called a kinetoplast I Includes fee living consumers in freshwater marine and most terrestrial habitats I Parasite Trypanosoma causes African sleeping sickness o Euglenids I Have one or two agella that emerge from a packet at one end of the cell I Stores the glucose polymer paramylon I Some species are mixotrophic o Alveolates have sacs between the plasma membrane 0 Dino agellates I Aquatic marine habitats I Diverse group of aquatic photoaurortophs and heterotrophs I Abundant components of marine and freshwater phytoplanton I Two agella make them spin as they move through the water I Rapid growth of some dino agellates is responsible for quotred tidesquot which can be toxic to humans such high concentration of them I Some dino agellates are bioluminiscent o Apicomplexans I Parasites of animals some cause human diseases 0 Plasmodium causes malaria I Apex contains a complex of organelles for penetrating host red blood cells I Apicoplast nonphotosynthetic plasmid Inside mosquito Inside human Sporozoites gt Merozoite n r 7 l 1 Apex Red blood o r n ell 7 7 i V I AGametes em 9 4 i m s Haploidn 39 o Diploid2n an to a cam Named furthelr use a allatu muve and feed same lntemal structure uf agella I Havetwunudel Maaanaeleas cuntxuls everyday laneaans M aanueleas uselncumugatlunrepmduc1lun Cunjuganunvs Regmdumun Themlcmnuda laneaan dunng cumugauun asexual pruness Lhatpmduces gamma Cumuganun ls separate rxam repraaaeaaa whlch genelally uncurs by blnary lassla Campanm Saultwill mllnl name Stramampilzs have hairy and smuuLh agella a Includes several guups ufheta39utxuphs as well as mam guups ufalgea a Diath Um cellular algea phutuaututmphs Slllcatest e pruduce a shell aruund them made ufslhca same Lhmgm sand Wldevanety afslmlla shzyes 0 Based offood chain in many manne ecosystems I Diatomaceous ea 0 ccumulated diatom tests in manne sediments 0 Used in toothpastes and lter media 0 Brown Algae Phaeophytes Largest and most complex algea All multicellular and mostly marine Seaweeds Altemation of Generations A variety oflife cycles have evolved among multjcellular algae diploidforms v I Devsluping pmaphyte Mature emails gametophm n Haploid n o niplold Zn 0 Cercozoans andradiolarians have threadlike pseudopodia O 39 39 i uu eamine pseudopodia false foot Foraminil39erans Named for their poious generally mumchambered tests shells made of calcium carbonate Pseudopodia extendthrough the pores in the test sea oor I Foram tests in marine sediments form an extensive fossil record 0 Radiolarians Marine protists With silica tests porous also I Pseudopodiaknown as axopo 39 0 Used to capture and phadocytose microorganisms o Amoebozoans have lobeshaped pseudopodia es gymnamoeb o Gymnamoebas as entamoebas and slime molds Have lobeshaped rather threadljke pseudopodia I Commonin soil as Well as freshwater and marine environments ost are heterotrophic M l s l M o Plasmodial Slime Prevmusly though to be mgi ass called a plasmodium o Coenoc ic multinucleate from the repeated division of nuclei Without cytoplasmic division one very large cell With thousands of nuclei throughout Extends pseudopodia through decompsing matter engul ng food by hagocytosis P I Life Cycle Flagellate cells 391 o Spores n I Light resistant I Surwve verydry o diti I When conditions becom 0 Cellular SlimeMolds I Fo eedlng F Mal plasmodium wasquot odium 39 preparing to Fruit f rv Vaung Amueboid cells H Germinating spore 7s sporangium Mature sporanglum Spares TEE EV W Stalk Hapluid n Diplnid 2n ons e more favorable the spores germinate rm multicellular aggregates cells separated by their membmnes I Dictyostelliumdiscoideum is an experimental model for studying the evolution of multicellularity v V zygote SEXUAL 2n 39 napnooucrlou Solitary amueuns silo AM u i Ueedl gstaga Fman SEXUAL M REPRODUCTION A9 m5alid nmnebas Mlgrallnn uggvagule o Questions 0 Whichofthefo ey o o o Nipluid I 200 pm Diplnld 2 t39 39 r39 r 288 M t 0 Red Algae rodophytes Redd39 ish in color due to accessory pigment called Ehycoe thdn Usually multicellular branchy leafy and corraline shapes Abundant in coastal mters ofthe tropics e red alga porphyra is eaten as crispy sheets or usedto wrap sushi Green Algae chlorophytes Named for their green chloroplasts chlorophyll a and b main pigments Divided into two main groups chlorophytes O T39 39 marine hahitat r quot quot Which undergone wl lichens charophytes o Ancestors oftenestrial plants llowing best describes most members ofthe Kingdom Protista are single celled and eukaryotic secondary endosymbiosis our plasma membranes Sexual reproduction in ciliates invol Dino agellets apicomplexans and ciliates are all placed in Have membran Altemation nf enemtinn 39 Bio org an Haploid g logists believe th isms ves e exchange ofhaploid micronuclei between two individuals the Alveolata because the all e u d sacs undertheirplasmamembranes it amete producing phase at green algae gave rise to land plants because both groups of n n I Contain chlorophyll39s a and b 0 Which protist moved by means of pseudopodia I One without agella or cilia but with uid protruding body appendages Ch 29 P 39 Febnlai y 15 ZHUS 10139 A Ch 29 Plant Diversity I How Plants Colonized Land Land plants evolved from green algae Concept 291 o Charophyceans have been identi ed as the closest relatives of land plants 0 Four key traits land plants share with Charophyceans I Roseshaped complexes for cellulose synthesis cell wall formation 0 Not found in chlorophytes I Peroxisome enzymes 0 Bread down hydrogen peroxide Structure of agellated sperm Formation of phragmatoplasts o Laid down in the cell plate dividing two cells 0 Genetic evidence I Comparisons of nuclear and chloroplast genes point to close relationship between charophytes and land plants 0 The Move to Land I Durable polymer sporopollenin found in charophyceans and land plants 0 Coating that prevents spores from drying out I Great opportunity for adaptive radiation 0 Sunlight unfiltered by water and plankton o Abundance of 02 o Nutrientrich soil 0 Few herbivores amp pathogens 0 Defining the Plant Kingdom I Systematists are currently debating the boundaries of the plant kingdom I Some want to include some or all of the green algae I We will use embryophyte definition of kingdom Plantae E Viridiplantae A Streptophyta Plantae 3 312 if Red algae Chlorophytes Charophyceans Embryophytes l Ancestral alga 0 Land plants possess a set of derived terrestrial adaptations 0 Five key traits appear in nearly all land plants I Apical meristerms 0 Tips of shoots and roots allow the plant to grow length wise I Alternation of generations 0 Haploid multicellular gametophyte stage to diploid multicellular sporophyte stage I Walled spores produced in sporangia I Multicellular gametangia o Gametophyte stage o Female archegonium and male antheridium I Multicellular dependent embryos o Nourished in the maternal tissue where fertilization took place 0 Trends in Plant Evolution I Green alga I Bryophyte o Sporophyte stage is limited to a very small dependent stage o Seedless nonvascular I Fern o Sporophyte is the dominant stage o Seedless vascular I Gymnosperm and Angiosperm o Dependent on sporophyte stage very small gametophyte stage Seed vascular Dependent on sporothyptespage Gametophytes of gymnosperms are found in the cones In angiosperms the gametophytes are found in the owers o The life cycles of mosses and other bryophytes are dominated by the gametophyte stage 0 Bryophytes are represented today by three phyla of small herbaceous nonwoody plants I Liverworts phylum Hepatophyta I Homworts phylum Anthocerophyta I Mosses phylum Bryophyta o Bryophyte diversity I Figure 299 o Bryophyte gametophytes I In all three bryophyte phyla gametophytes are the dominant stage of the life c cle I Produce agellated sperm in antheridia and ova in archegonia I Form ground hugging carpets and at most are only afew cells thick 0 Nonvascular plants so have to remain very small because water is distributed to the body of the plant through diffusion o Bryophyte sporophytes I Grow out of archegonia I Consist of a foot a seta and a sporangium 0 Foot anchors itself within the gametophyte o Seta is the long stalk o Sporangium is the capsule at the very end of the seta I Homwort and moss sporophytes have stomata I This is a nonphotosynthetic stage that is just for producing spores for the dispersal Class Example All of the following are seedless nonvascular plants except Lycophyta 0 Moss life cycle Ham 7 Human n Dlp39old 2n Mala garnnlonhylc quoti Gnmelophora 7 Female Archcgonm g malophyle V unlzum Perlslom wl ch aonlum zygmu spavophvln swam Foo i Embryn l I quot Archn unlum 39 74 m S C I calypua Mature Y Pan39sgn 39 chnu sperephylo capsule wnh chnln perlsluma LM gsmelophylet Class Example Which of the following statements is correct regarding the bryophytes e bryophytes represent a monophyletic clade The sporophyte stage of all bryophytes is photosynthetic Archegonia and antheridia are haploid structures that produce reproductive cells Stomata are common to all bryophytes Concept 293Ferns and other seedless vascular were the rst plants to grow tall 0 Life cycles with dominant sporophytes I Sporophytes of seedless vascular plants are the larger generation I The gametophytes are tiny plants that grow on or below the soil surface 0 Classi cation of seedless vascular plants I Two phyla o Lycophyta club mosses spike mosses and quillworts o Pterophyta ferns horsetails and whisk ferns o Fern life cycle Kiay Haploid n Diploid 2n 34 9 Spare Youn gametophyte Antheridium Mature New sporophyte sporophyte o Fiddlehead o Innovations in vascular plants I Vascular plants have two types of vascular tissue 0 Xylem conducts most of the water and minerals from the soil up into the sporophyte stage and into the branches 0 Phloem distributes sugars amino acids and other organic products I Roots 0 Anchor vascular plants 0 Absorb water and nutrients from the soil I Leaves 0 Increase surface area for capturing more sunlight 0 Signi cance of seedless vascular plants Ancestors of modern lycophytes horsetails and ferns formed the first forests during the carboniferous I Decayed and became coal 0 Questions 0 In the diagram which box represent reduction division from a diploid to haploid state I A spore mother cells undergo meiosis to create spores that develop into gametophytes 0 Which of the following is a land plant that produces agellated sperm and has a sporophytedominated life cycle I Pterophyta o Ferns horsetails o Sporophyte dominated stage I Bryophyta o Seedless o Nonvascular 0 Dominant gametophyte stage I Anthocerophyta o Seedless o Nonvascular o Gametophyte dominant stage I Charophycean o Algae 0 Ch 30 Thursday February 38 2mg a 713 PM 0 Chapter 30 Plant diversitv II the evolution of seed plants 0 The reduced gametophytes of seed plants are protected in ovules and pollen grains 0 Characteristics common to all seed plants I Seeds I Reduced gametophytes microscopic I Heterospory I Ovules I Pollen o Gametophytesporophyte relationships I Gametophytes of seed plants develop within the walls of spores retained within tissues of the parent sporophyte Provides protection from drought conditions and UV radiation 0 Dependent gametophyes obtain nutrients from the sporophyte I No longer dependent on water for fertilization I Figure 302 o Heterospory the rule among seed plants I Seed plants evolved from plants that had both megasporangia female J 39 es and 39 r 39 male 39 f I Page 586 o Heterosporous species have two types of sporophyll leaves that bear sporangia and produces two kinds of spores o Heterosporous spore production r 39 in r r39 yllgt r gtFemale gametophyte gt Egg 0 Megasporangium in microsporophyll gt Microspore gt Male gametophyte gt Sperm o Ovules and production of eggs I An ovule consists of a megasporangium megaspore and protective integuments I Figure 303a o Pollen and production of sperm I Microspores develop into pollen grains 0 Contain the male gametophyte I Pollen can be dispersed by air or animals eliminates the water requirement for fertilization o Coated with the sporopollenin polymer that keeps them from drying out so that they can be dispersed by wind or by animals 0 If a pollen grain germinates I It gives rise to a pollen tube that discharges two sperm into the female gametophyte within the ovule I Figure 303b o A seed I Develops from the whole ovule I Includes sporophyte embryo food supply protective coat I Figure 303 layers 0 Seed coat derived from integument 0 Food supply female gametophyte tissue n o Embryo 2n new sporophyte o The bryophytes mosses have independent 7 as well as attached dependent I Gametophytes sporophytes I Sporophytes gametophytes I Rhizoids zygotes I Antheridia archegonia 0 Which does not apply to gymnosperms or angiosperms I Vascular tissues I Diploid dominance I Single spore type homosporous I Cuticle with stomata o Gymnosperms bear naked seeds typically on cones o Gymnosperm means naked seed 0 Gymnosperms include I Figure 304 I Ginko o Gymnosperm evolution I Fossils reveal that by the late Devonian period plants called progymnosperms had some characteristics of seed plants I Gymnosperms dominated Mesozoic terrestrial ecosystems 0 Known as the age of cycads I Figure 305 progymnosperm heterosporous produced wood femlike leaves no seeds 0 A closer look at the life cycle ofa gymnosperm I Key features of the gymnosperm life cycle include o Dominance of the sporophyte generation 0 The role of pollen in transferring sperm to ovules o No water required for reproduction unlike seedless plants that require water for reproduction o The development of seeds from fertilized ovules 0 Pine life cycle I Figure 306 I Representative of a gymnosperm life cycle I Mature sporophyte stage that is diploid o On the sporophyte are the ovulate cones female and pollen cones male 0 Within each cone scale are the microsporocytes diploid 7 cells that undergo meiosis to form the haploid spores that are developed into the pollen grain o In the pollen grain is the male sporophyte stage 0 How many generations are represented in the seed of a gymnosperm I 3 o Embryo new sporophyte 2n 0 Food supple female gametophyte n 0 Seed coat derived from parent sporophyte 2n 0 Coal consists primarily of compressed remains of the ithat dominated Carboniferous swamp forests I Seedless vascular plants I Seed bearing plants I Nonvascular plants I Angiosperms o The reproductive adaptations of angiosperms include owers and fruits o Angiosperms aka owering plants I Means covered seeds 0 Derived traits are the reproductive structures called owers and fruits o The most widespread and diverse of all plants I 250000 species I 90 of all extant plant species 0 Flowers I Specialized structure in angiosperms for sexual reproduction I Specialized shoot with modified leaves 0 Sepals 7 enclose the ower 0 Petals 7 brightly colored attract pollinators o Stamens 7 produce pollen o Anther terminal sac where pollen is produces o Filament stalk o Carpels 7 produce ovules o Stigma sticky tip that receives pollen 0 Style long stalk connecting stigma and ovary o Ovary base of carpel contains one or more ovules o Receptacle all whorls of the oral organs attach to the stem at this point I Figure 307 0 Fruits I Typically consist of a mature ovary o Ovary matures after fertilization of ovules I Can be carried by wind water or animals enhancing dispersal I Figure 308 and 309 o The angiosperm life cycle I Double fertilization occurs when a pollen tube discharges two sperm into the female gametophyte within an ovule 0 One sperm fertilizes the egg 0 Forms 2n zygote 0 Second sperm combines with two polar nuclei in the center cell of the female gametophyte and initiates development of endosperm 0 Forms a triploid tissue 3n that develops into the endosperm o Endosperm nourishes the developing embryos I Figure 3010 0 Angiosperm evolution I Angiosperms originated at least 140 MYA and diversified during the late Mesozoic I 125 MY old fossils show some derived traits found in modern angiosperms I Figure 3011 o Angiosperm diversity I Figure 3012 Gymnosperms and angiosperms have the following traits in common except 0 Seeds I All are seed bearing plants 0 Pollen I Adaptation of all seed bearing plants 0 Vascular tissue 0 Ovaries I Derived characteristic in angiosperms only 0 Ovules I Where the female gametophytes are With respect to angiosperms which of the following is incorrectly paired with its chromosome count 0 Egg cell 7 n O Megaspore 2n I Should be 11 megasporocyte has 2n 0 Microsporocyte 7 2n 0 Endosperm 7 3n Ch 31 39I39hursdny February 2008 73917 PM 0 Ch 31 Fungi o How many individual fungi do you see in this picture 0 1 Mushrooms that are sticking up above the ground are just the reproductive structures of one fungi that is underground 0 o 46 o 52 o Fungi are heterotrophs that feed by absorption 0 Fungi are heterotrophs but do not ingest their food Secrete exoenzymes into their surroundings that break down complex molecules Absorb smaller organic molecules 0 Fungi exhibit diverse lifestyles Decomposers aka saprotrophs Parasites Mutualistic symbionts o Fungal nutrition and lifestyles Fungi and heterotrophs but do not ingest their food 0 Secrete exoenzymes into their surroundings that break down complex molecules 0 Absorb smaller organic molecules 0 Body structure The morphology of multicellular fungi enhances absorption of nutrients Fungi consist of hyphae that are grouped together in mycelia 0 Long thin filaments that branch 0 Maximizes the surface area Most fungi have cell walls made of chitin Figure 312 Some fungi have hyphae divided into cells by porous septa with pores allowing cell to cell movement of materials Coenocytic fungi lack septa Figure 313 0 Which ofthe following is a job not performed by any fungi Decomposer Parasite Predator 7 some will capture a prey and digest it Producer there are no photosynthetic phototrophic 0r photoautotrophic fungi all fungi are heterotrophs o Specialized hyphae Some fungi have hyphae that allow them to capture animals and penetrate the tissues of their hosts Mycorrhizae are mutualisms between fungi and plant host 0 Ectomycorrhizae surrounds root cells 0 Endomycorrhizae extends hyphae through root cell wall Figure 314 o Fungi produce spores through sexual or asexual life cycles 0 Generalized fungi life cycle Figure 315 Produce spores in two ways o Asexual reproduction 0 Lecture I Most fungi have a haploid mycelia I Need to disperse their spores I Certain structures on the haploid mycelium are spore producing structures Bud off tiny spores that can be dispersed Land on a suitable habitat bread and germinate to form another haploid mycelium 0 Many fungi such as molds produce spores asexually on conidia Singlecelled yeasts reproduce by buds Molds and yeasts with no known sexual stage are classi ed as deuteromycetes or imperfect fungi 0 Sexual reproduction o The sexual life cycle involves I Cell fusion 7 plasmogamy 7 fusion of two cells but not fusion of their nuclei cell with two haploid nuclei I Nuclear fission 7 karyogamy 7 two haploid nuclei fuse together to form the diploid zygote o Heterokaryotic stage is between plasmogamy and karyogamy I Cells have haploid nuclei from two parents 0 The diploid phase following karyogamy is short lived and undergoes meiosis producing haploid spores 0 Which phylogenetic tree represents the evolutionary history of these taxa based on the most recent data I l I 2 I 3 most recent evidence puts fungiwith the animals 00 o Fungi descended from an aquatic single celled agellated protist o The origin of fungi I Systematists now recognize Fungi and Animalia as sister kingdoms I Molecular evidence supports the hypothesis that fungi and animals diverged from a common ancestor that was unicellular and bore agella o Fungi have radiated into a diverse set of lineages 0 Figure 319 o Chytridss I Fungi classified in the phylum Chytridiomycota I Found in freshwater and terrestrial habitats I Saprobic or parasitic o Decomposers I Unique in having agellated spores called zoospores I Figure 3010 I Once thought that chytrids were monophyletic and ancestral group to other fungi o Fungi lost their agella once I Molecular evidence suggests that some chytrids are closely related to zygomycetes I Figure 3111 o Zygomycetes I Fungi in the phylum Zygomycota I Diverse life histories I Include molds parasites and commensal symbionts I Named for their sexually produce zygosporangia I Life cycle of Rhizopusstolom39fer I Figure 3112 I Zygosporangia develop a rough thick coat that can withstand harsh conditions for months I When conditions improve they undergo karyogamy then meiosis and produce a sporangium o Glomeromycetes I Fungi in the phylum Glomeromycota I Once considered zygomycetes now classi ed in separate phylum I Form distinct type of endomycorrhizae called arbuscularmycorrhizae I About 90 of all plants have mutualistic relationship with gomeromycetes I Figure 3115 0 Ascomycetes I Fungi in the phylum Asomycota also known as sac fungi because form sac like shapes 8 haploid spores I Found in marine freshwater and terrestrial habitats I De ned by the production of sexual spores in asci contained in ascocarps I Figure 3116 7 Ascomycete diversity I Ascomycetes reproduce asexually by producing enormous numbers of asexual spores called conidia I Ascomycete life cycle Figure 3117 0 Basidiomycetes I Phylum Basidiomycota aka club fungi I Includes mushrooms and shelffungi I Defined by clublike structure called a basidium I Mycelium is usually long lived and dikaryotic 0 Can send up mushrooms in just a few hours I Basidiomycete diversity 7 Figure 3116 I Basidiomycete life cycle 7 Figure 3120 0 Your parents are coming to visit and you immediately run to the pantry to throw away the loaf of bread with the black fuzzy stuff on it What phylum of fungi did you just trash I Basidiomycota I Ascomycota I Zygomycota 0 Typically form bread mold I Chytridiomycota o Fungi have a powerful impact on ecosystems o Fungi are well adapted decomposers of organic material I Breaks down dead material I Recycles chemical elements between living and nonliving portions of ecosystems o Fungi form symbiotic relationships with plants and animals 0 Mycorrhizae I Mutualisms between fungi and plant host ooum Increase plant productivity Figure 3 121 o FungusAnimal symbioses Some fungi help break down plant material 0 Guts of cows and other grazing animals Some ants and termites raise fungi in farms 0 Lichens Symbiotic association between photosynthetic microorganisms and a fungus Very hardy organisms that can occupy harsh environments Three general growth forms 0 Fruticose o Foliose o Crustose Figure 3123 The fungal symbionts is most often an ascomycete Singlecelled green algae or cyanobacteria are the photosynthetic symbionts Asexual reproduction by fragmentation or release of soredia Figure 3124 In seed bearing plants microspores develop into 0 Ovules 0 Seeds 0 Pollen grains 0 Anthers Ch 33 Wednesday February 37 2108 942 AM Ch 33 Invertebrates Most Recent Hypothesis About Animal Phylogeny 0 Figure 3211 Sponges are sessile and have porous body and choanocytes Concept 331 o Phylum Porifera Only organized at the cellular level no tissues Live in both fresh and marine waters Lack true tissues and organs organized at cellular level Asymmetrical body plan grow dependent on the environmental conditions 0 Spon ges Sponges are suspension feeders Filter water passing through their bodies Porocytes dough nut shaped cells that span the body wall Chanoeytes line the spongocoel movement of agella sets up water ow Chaonocytes trap food and ingest it by phagocytosis pass it along to ameobocytes Ameobocytes transport nutrients to other cells secretes spicules Spicules skeletal elements that determine the structure Flagellum Food particles in mucus Choanocyte Chnanucytes Axure vase sponge Callyspongia plicilera Spongocuel Phagucyiusls of mod partlcles Amoehocyie Porocyles Amoehocyte 1 T ovement through a sponge Wouldfollow What path Poroeytegt spongoeoel gtosculum Cnidarians have radial symmetry a gastrovaseular cavity and enidoeytes Concept 332 0 Water m 39 ange of sessile and floating forms ineludingjellyf39ish corals and hydras 39 Simple diploblastie radial body plan 0 Diploblastic two tissue layers outer epidermisrn and inner endoderrnis 0 Body plan is a sac with a central gastrovaseular eavi oquotp39 and 39 watc depositedf39rom same opening 0 Mesoglea layer between epidermis and endoderrnis o Cnidarian Body Plants Polyp form is generally sessile immobile form Medusa fo moves freely in Water by passive drifting and contractions of the bell mobile for Bo forms m have endodermal and epidermal layer with mesoglea layer in between and have a gastrovaseular cavity uulhlanus Tentacle Medusa Gasiravascular cavin Gastrodermis mesoglea 0 De ning Feature of Cnidarians 39 Cnid es Uni e cells that function in defense and the capture of prey o 39 Stimulus causes the cell to evert releasing thread Some cnidocytes sting others just entangle the prey o ome of the most toxic species on the planet 04 Tentacle Trigger Nematocysl Coiled thread x q Dlscharge of thread Cnidocyle o Cni danan Diversity class IIydroma HI e Class and Examples Classes of Phylum Cnidaria Main Characteristics Hydrozoa Portuguese man oqur hde39ns Olk liu some corals see Figures 3372 an 338 Scyphozoa jellies sea mules sue Figure 33713 Cubozon box jellies sea wasps scc Figure 317 Anthozoa sen anemones most comls sea ans see Flgure 337d b Many sperles ol yelhes class Scyohozqa mclud he Most marine a few freshwater both polyp and mmlusn stages In most species polyp stage often cnlunia All marine polyp stage reduced roeswimming medusne up to 2 m in diameter All marine box 121 cd medusae complex eyes g All marine mcdusa stage completely abscnl most sessxle many colonin c The sea wasp Chironex flecksr vs a membev a class large prey l5 move pnlem Ihan Cobra venom body up to 2 m m dlarnezer L quot l r39 hydmzoan L39 L 39 39 uenee swimming I Medusa How man a i will quot 39 39 39 39 symmetry into roughtly equal halves Many cutting aradial symmetric organism will produce identical halvesno matter its cut 0 Most animals have bilateral symmetry Concept 333 Most animals belond to the bilateral clade tissue becomes concentrated towardsone end of the body head Tiploblastic development tissue layers Ectod uter layer Mesoderm middle Endoderm inner o o limm encasiral wioniall on polls 0 atworm t s p ylum Platyhelminthes Live in marine freshwater and dampterrestrial habitats some parasitic live inside I 1 u 411k x a it cavity Class Turb ellaria 0 Most free living marine and freshwater worms o ave Lightsensitive eyespots o Centralized nerve net with anterior ganglia o Gastrovascular cavity with two way pharynx 0 Class T O VIntrul Mm conic rematoda Blood uke schistosoma mansoni life cycle 0 Mature Nukes live in the blood vessels of the human intestine i Doesn39t cause much harm to humans unless hard coatings of eggs scratch intestines as they are passed Tapew Rotifer orms Class Cestoidea Infect humans through improperly cooked meat Scolex end of worm attaches to the host Proglottids are the reproductive structures testes amp ovaries selffertilization Break off after ferlitization s Phylum Rotifera Microscopic animals that inhabit aquatic habitats Smaller than most protists Alimentary canal with separate mouth amp anus Pseudoceolomate tripoblastic development with cavity between endoderm and mesoderm called pseudoderrn serves as hydrostatic skeleton where inner organs lie Reproduce by parthogenesis females produce offspring from unfertilized eggs 0 Question Which ofthe following 39 39 1 pn 1a and 39 39 j LuLUUcLL I Porifera gastrovascular cavity two tissue layers sponges do not have cavity no tissue only organized as cellular level 0 Molluscs have a muscular foot avisceral mass and a mantle Concept 334 o Mantle a fold of tissue that drapes over the visceral mass and secretes a shell if present 0 N ephridium removes metabolic wastes from hemolymph O NervousSystem nerve ring around the esophagus and ventral nerve cord 0 Opencirculatory system heart pumps hemolymph circulatory uid through arteries and into sinuses body spaces 0 s and scoops food Radula rasplike feeding organ in mouth scr C elom Nephridium 7 V Stomach 9 ewe Esophagus cords 0 Class Polyplacophora I Aka Chitons I Marine molluscs typically on rocky shores use suction 0 an roll themselves in protective shell if they are separated from rocks Shell has 8 plates Foot used for locomotion Radula scrape algae ofrocks No true head O 0 Class Gastrophoda I Snails and slu s I Marine freshwater and terrestrial I Asymmetrical body usually with a coiled shell Result of torsion rotation of the visceral mass Foot for locomotion Radula scrape up organic typically plant matter for food Some have modified radula that can be shot out and is poisonous Stomach Intestine Mantle cavity 0 Class Bivalvia I Clams mussels scallops oysters Marine and freshwater Flattened shell with 2 valves connected by hinge Head reduced No radula no scraping of food Mostly suspension feeder suck in water through siphon trap in food particles through gills and secrete waste water Coelom Hinge area manna Gm H93quot Adductor Mouth Excu rrent Mantle lncurrent o cavity Gm siphon 0 Class Cephalopoda I Squids actopods cuttlefish chambered nautili I Marine I Head surrounded by grasping tentacles 0 Usually with suckers o Can capture moving prey I Shell may be external internal or absent 0 Annelids are segmented worms 0 Ceolomate body cavity I Outer ectoderm I Inner endodermal layer I Mesodermal layer lines the inside of the ectoderm and the outside of the endoderrn and is connected by a mesentary than encloses the ceolem 0 Anatomy of an Annelid Earthworm I Body is divided into segments 0 Each segment has a set of muscles 0 Contract against ceolomic uid hydrostatic skeleton o More complex movement with segments than atworm without I Closed circulatory system with 5 pumping vessels hearts I Alimentary canal w specialized regions 0 Mouth at one end digestive tract runs length of body anus at the opposing end 0 Different regions of tract are specified for different purposes storage grinding absorption elimination o Allows them to eat more food I Figure 3323 0 Annelid Diversity Table 334 I Oligochaete o Earthworrns 0 Very small bristles that project out its segments and help it to burrow into the soil and stay anchored I Polychaetes 0 Each segment has a parapodium foot that radiates from each segment with large chaete that help them swim through water and for defense 0 More de ned head region I Hirodinea o Leaches o Parasitic predatory Arthropods are segmented coelomates that have an exoskeleton and jointed appendages Concept 337 0 Two out of every three known species of animals are arthropods I Table 335 0 General Characteristics of Arthropods I Diversity and success is related to their segmentation exoskeleton and jointed appendages I Early arthropods showed little variation among segments I Trend in arthropods evolution has been fusion of segments and specialization of appendages o Craw sh pinchers for defense swimming appendages walking legs I Arthropod body is covered by an exoskeleton made of chitin 0 Support structure of the body 0 When an arthropod grows it sheds the exoskeleton by a process called ecdysis must shed to grow I Arthropods have an open circulatory system 0 Hernolymph is circulated into spaces surrounding tissues by pumpheart o No vessels that carry the uid as in a closed system I Variety of gas exchange organs 0 Gills aquatic exchange C02 and oxygen with water 0 Tracheal tubes set of tubes that run throughout the body and exchanges air without outside environment 0 Book lungs gas exchange occurs across thin membranes that resemble the pages ofa book 0 Subphylum Cheliceriformes I Horseshoe Crabs Scorpions Spiders Ticks Mites I Characterized by Chelicerae pinchers that are used for capturing prey and defense I Arachnid Anatomy I o Subphylum Myriapodia Spiders scorpions ticks and mites Body has 2 regions 0 Cephalothorax o Abdomen Cephalothroax has 6 pairs of appendages o Pedipalps O Chelicerae fangs o 4 pairs of walking legs Book lungs for respiration thin membranes with capillaries Stomach Intestine 7 Book lung Spinnerets Silk gland Chelicera Pedipalp nopore exit for eggs Sperm receptacle I Millipedes amp Centipedes I Millipedes Class Diplopoda 2 pairs of legs per segment Detritus feeds dead organic matter in leaf litter I Centipedes Class Chilopoda 1 pair of legs per segment Camivores eat other animals very painful and sometimes poisonous bite o Subphylum Hexapoda I Insects and their relatives have 6 walking legs I More species rich than all other animals I Insect Anatomy Insects are characterized by having 3 pairs of walking legs on the thorax l or 2 pairs of wings 3 body regions abdomen thorax head Open circulatory system Tracheal tube gas exchange through spiracles on sides of body Ventral nerve cord Cephalization with cerebral ganglion Abdomen Thorax Head Compound eye Antennae Duvsal artery 39 P Cerebral gangliol Malpighian rubuIes Moulhpans Tracheal tubes Nerve cords o o Subphylum Crustacea I Mostly marine and freshwater Biramousappendages two extensions offofone appendage Gills for gas exchange Craw sh lobster crabs shrimp krill barnacles Cephalmnnrax Abdomen WaIkIg legs 0 Pincer defense Muu hPMS Wading 0 Three ofthe four animals listed belowpossess some type of coelom Select the exception I elids Arthropods u cs altyhelminthsectoderm endoderm and mesoderm only Echinoderms and chordates are deuterostomes Concept 338 0 Echinoderms may not look like chordates which includes vertebrates but they share a E 0 common developmental p an O Deuterostomes I Radial cleavage Ceolom develops from archenteron Mouth forms opposite of blastopore anus Know the gure Protoslome developmenl Deulerosmme development examples molluscs annelids examples echinoderms arthropods churdalesl a Cleavage b Coelom formation c Fate of the blastopore my In u ma r o Phylum Echinodermata I Echonoderm spiny skin I Slow moving or sessile marine animals I Pentaradial symmetry I Unique watervascular system series of tubes running through the arms for locomotion capturing prey and attaching to substrates Central disk Madreporile Digestive glands Radial Radial canal O o Echinoderm Diversity I Table 336 I Sea stars Brittle stars echinoid sea urchins crinoids feather stars sea cucumbers concentric cycloidia 0 Summary of Animal Phyla mm nsmmmn MW umummwau w WW UM WWW w W k y n m 4 Wmmwwwm m WW UmmnmmvWm m m WNW m M k W r kmwmmhn m u w vmmm w Wmnmm WWW WWW mm M W 4 m WWW W n u amykmhynw lkww mm mm mm m mm mm W mm W W Mm WM a memmu W t n W mm mm mm my mum wquot 5 m WNW mm A man r hquot M M mg 1 mm mm mum h mm mum mm Wm mm mm hmem mm mm mm mm A mm WNW mm quot mwym mva L H mm m Mm A MWWWW M mm W b m WW m m 3 m F L m mmmm Wm w 3 WWW v WWW 4 WMm a Ar um w quotm Whmh cme fulluwmg characteristics 5 nut true ufall ammzl phyla 7 a MLLlucellulax u an System Puritan a Hetautxupm a anlmd Cmdanzns du nuhzve a Tantacle equipped with nematucysts Tree assm layers Diplnhzstic r twn laya39s Ramal symmetry A gamuvascular system m1 buayexgmamsa1 plates gala un rucky EDESLS m descriptive uf a Fulyplacuphura Ch 34 MandayJHhrchEll mnz 9 41 AM Ch 34 Vertebrates Which of the following statements is not true 0 All chordates have vertebrae not true 0 All chordates have notochords pharyngeal pouches and postanal tails true Chordates have a notochord and a dorsal hollow nerve chord o Chordates are deuterostomebilaterian animals bilateral symmetry o 2 chordate subphyla are invertebrates I Urochordata I Cephalochordata o Vertebrata is also a subphylum of Chordata with vertebratae o Derives Characters of Chodates I All chodates share 4 derived characters Dorsal hollow Muscle nerve cord segments Notochord Anus Pharyngeal cular slits or cle s postanal tail 0 Although some species posses some of these traits only during embryonic development Tunicates I Subphylum Urochodata I Deepestbranching lineage of chordates I Sessile marine suspension feeders Draw water in through incurrent siphon filtering food particles Only chordata characteristic seen in adult stage is the pharynx with slits Tunicates posses the chordate characteristics during their larval stage 0 siphon lo mouth Excurrent I a b 0 Which of the following is a diagnostic feature of the tunicates that forms the basis for its classification as a chordate No Dorsal hollow Excurvenl slphon ul Incurrenl I j slphon Pharynx wilh slll I A notochord located along the dorsal part of the larva o Lancelets I Subphylum Cephalachordata I Marine suspension feeders I Retain chordate features throughout lifespan Figure 345 o Craniates are chordates that have a head Concept 342 o The origin of the head in chordates allowed some to become active predators 0 Shared characters in craniates I Skull I Brain I Eyes amp other sensory organs 0 Hag shes I Class MyXini I The least derived eXtant species of Craniate I Jawless marine craniates I Cartilaginous skill and aXial rod derived from notochord I No vertebrae o Vertebrates are craniates that have a backbone Concept 343 0 Characteristics I Vertebrate enclosing a spinal chord I An elaborate skull I Fin rays in aquatic forms 0 Lampreys I Class Cephalaspidomorphi I Oldest living lineage of vertebrates C quot 39 segments quot I notochord and arching partly over the nerve chord Jawles s I Found in marine and freshwater o Origins of Bone and Teet Mineralization appears to have originated with vertebrate mouthparts o Conodonts were lst with mineralized mouth and pharyngeal parts 0 Ostracoderms had mineralized plates on their skin I Endoskeleton became mineralized later Dental elements 0 The most primitive but still existing craniates are members of the class I MyXini hag sh o Gn athostom es are vertebrates that have jaws Concept 344 0 O 0 Most successful group of vertebrates alive today Derived Characters of Gnathostomes I Jaws o Evolved from skeletal supports of the pharyngeal slits I Enhanced sensory system including lateral line system I Mineralized endoskeleton I Paired appendages Chondrichthyans Sharks Rays and their relatives I Class Chondrichthyes 0 Means quotcartilage shquot skeleton made of mostly cartilage I Includes sharks rays and r39at shes I Sharks are streamlines and swift simmers I Rays are dorsoventrally attened Most vertebrates belong to the clade called Osteichthyes I Including ourselves tetrapods terrestrial vertebrates I Have bony endoskeltons I Aquatic osteichtyans o Vertebrates we call sh ray nned sh and lobe ns 0 Have a swim bladder for bouyancy control I Ray Finned Fishes 0 Class Actinopterygii o Familiar aquatic osteichthyans o Fins supported by long exible rays 0 Seahorse eel Figure 34 17 I Lobe Fins 0 Class Sarcapterygii o Rodshaped bones surrounded by muscle in pectoral and pelvin fins 0 Coelancanths lung sh freshwater air sacs are rudimentary lungs can live brie y on land tetrapods terrestrial vertebrates lobe fin sh gave rise to them Shark skates and rays belong to the class I Chondrichthyes cartilage bone sh 0 Tetrapods are gnathostomes lob n sh that have lirnbs and feet Concept 345 0 O O Derived Characters of Tetrapods Four lirnbs snd feet with digits I In some forelimbs are modi ed for grasping bipeds or ight birds I Ears for detecting airborne sounds o No lateral line system detects vibrations in the water I Figure 3419 Acanthostega 0 See complete tetrapod limbs 0 Early amphibian Origin of Tetrapods I Based on fossil discoveries I Figure 3420 I Tictalic transition between most aquatic and mostly terrestrial tetrapod bones that can support weight on land for short periods of time Amphibians I Class Amphibia o Considerably amount of time spent in water and on land Represented by about 4800 species Order Urodela salamanders Order Anura fords and toads Order Apopda caecilians group that has adpoted a burrowing lifestyle much like a worm ga exchanges skin must remain moist 39 39 t u i e 39 39 39 habitats Tied to water for reproduction Eggs desiccate out of water Larvae are o en aquatic Can move out ofwater onto dry lanolin adult stage l t r MThE iodpole l5 s squall nemlvow wlm o llslililre Vall nd mtemal pills aw p A r a r 39 1 t l a the male grasps llle lemale mmuhnng he o release eggs the egg is Dining melammumsls he gills arc Inld and fcm tzed n mist wet have a i39ellv em but lack a shall anu ull are reroroei and waiting and would daslrrare w alt legs demo 0 If an amphibian could be a plant which plant would it be M quoted to water for reproduction Monocot Cynad Cmetophyte seed bearing vascular plants 0 Derived characters ofAmniotes Amniotes get their name from the amniotic egg o Amnion protects the embryo in a uid lled cavity 0 Allamois disposal sax for certain metabolic wastes Also functions with chonon as a respiratory organ 0 Chorion exchanges gases between embryo andthe air 0 Yolk sac provides nutrients for the developing embryo Exlvaamnrynnl membranes Amnlon Allamois chonon Volk sac Amniolic cavin with amninlh lluid Vqu rlulrienls o o Relatively impermeable skin O o Reptile Ability to use rib cage to ventilate the lungs s The reptile clade includes the tuatara lizards snakes turtles crocodilians birds and the extinct dinosaurs Have scales that create a waterproof barrier tough and leathery Lay shelled eggs on land Mostly ecototherrnic o Absorb external heat as the main source of body heat 0 Exception is the birds which are endothermic The Origin amp Radiation of the Reptiles Figure 3423 Turtles 0 The most distinctive group of reptiles alive today 0 All turtles have a boxlike shell made of upper and lower shields that are fused to the vertebrae clavicles and ribs 0 Both aquatic and terrestrial species Diapsid Reptiles o Composed of2 groups 0 Lipidosaurs I Tuatoras lizardlike reptiles I Squamates lizards and snakes o Archosaurs I Includes the Dinosaurs extinct and the living crocodilians and birds I Birds 0 Birds are archosaurs 0 But their anatomy has undergone modi cations in their adaptations for ight that reduce weight 0 No urinary bladder 0 Females have 1 ovary o Males and females have small gonads 0 Light skull and no teeth Adaptations for Flight 0 Most obvious adaptation for ight are the wings and feathers Bird Lungs Living Birds 0 Ratites are all ightless birds 0 Birds that do y have a similar body form 0 Considerable variation in food structure depending on lifestyle 0 Figure 3430 and 3431 0 Why is the amniotic egg considered an important evolutionary breakthrough Has shell that increases gas exchange 0 Mammals are amniotes that have hair and produce milk Concept 347 Derived Characteristics 0 O 0 mary glands that produce milk Hair and insulating layer of fat beneath skin Diaphram to help ventilate the lungs Generally larger brain than other vertebrates of equivalent size Extended care period for young Differentiation of teet Early evolution of Mammals Mammals evolved from synapsid reptiles Modification of the jaw bons in distinctive in mammals O O O O O O I Figure 3432 Phylogenetic Relationships of Mammals I Figure 3436 Monotremes I Include the platypus and spiny anteater 0 Lay leathery eggs 0 Nourish young with milk but nipples Marsulpials I Include apposums kangaroos and koalas I Young are born very early in development and crawl to marsupium I Development is completed within the pouc I Figure 3434 and Figure 3435 Eutherians Placental Mammals I Eitherians have a longer period of pregnancy I Eutherians complete embryonic development with a uterus joined to the pother by a placenta I Major Eutherian Orders Figure 3436 Which is NOT characteristic of all mammals I Give birth to live young viviparous 0 Some lay eggs The term agnathan can be used to describe I Conodonts and myXini jawless 0 Ch 35 llnm Monday March 10 200839 946 Ch 35 Plant Structure Growth and Development The plant body has hierarchy of organs tissue and cells Concept 351 0 The Tree Basic Plants Organs Figure 352 I Plants draw nutrients from 2 very different environments below ground and above ground I 3 basic organs Root Stems Leaves I Organized into the root amp shoot system Below root system Take mineral nutrients from the soil Above shoot system Made up of stems and leaves main photosynthetic organs I Roots An organ that anchors the vascular plant Absorbs minerals and water 0 Absorption occurs near root tips Stems Leaves I o Rout hairs increase the surface area of the root Stores organic nutrients o ie Carrots store organic materials so it can survive during the winter Modified Roots 0 Prop Roots above ground there are roots coming off of the stem help keep the plants upright arze corn 0 Storage Roots large eshy roots that are storing nutrients for winter I Sweet potatoes 0 strangling aerial roots most of the mass is above ground roots are send all over plants and structure that strangling them I Strangler fig 0 Buttress roots help support the weight of the tree above ground in environments with weak soil I Ceiba tree 0 Pneumatophores soil is water logged like in swamps part of the roots that come up above the water to get the oxygen 1t nee s I Cypress trees Roots are invovled in all but which of the following activities 0 Food production Figure 352 Part of the shoot system Nodes points at which leaves are attached Internodes segment between notes Axillarybuds potential to form lateral shoots ie branch Terminalbud apical meristem located at shoot tip causes elongation of a young shoot 0 Contributes the most to the growth of the plant 0 If the terminal bud is removed then the axillary buds will sprout and grow Modified Stems Figure 355 0 tolon horizontal stems that grow above ground parallel to ground at nodes they will send up shoot systems runners enable plant to reproduce asexually I Strawberry plant 0 Bulbs vertical underground shoots consisting mostly of the enlarged bases of leaves that store food I Onion 0 Tubers extension from the root system store carbohydrates I otatoes O Rhizomes horizontal thickened stem for storing organic material below ound I Ginger The leaf is the main photosynthetic organ of most vascular plants thin and at to maximize sunlight absorption Consists of o A attened blade 0 The petiole which joins the leave to a node of the stem Simple vs Compound Leaves Figure 356 0 Simple leaf a single undivided blade I Some may have deep lobes 0 Compound leaf blade consists of multiple lea ets 0 Double compound leaf each lea et is divided into smaller lea ets o All only have one axillary bud lets you know which type it is Modified Leaves Figure 357 Tendrils lasso supporting structures long stringlike leaves that will wrap around a structure help keep plant upright Pea plants O o Spines serves for protection help with water conservation since most water is lost from the leaves long slender leaves retain I Cactus 0 Storage succulent plants have thick leaves that store water 0 Bracts attract pollinators colored leaves I Poinsettias o Reproduction little plantlets form on leaves that drop off and become new ants The Three Tissue System Dermal Vascular and Ground Figure 358 Dermal consists of the epidermis and periderm outer layer Serves from protection from diseases and microbes and water rentention Helps in the absorption of water and minerals Vascular carries out transport of materials between roots and shoots Xylem conveys water and minerals up from the roots Phloem transports organic nutrients from sources usually leaves to sinks roots round various function including storage photosynthesis and support 39 G o Differentiated Plant Cells Figure 359 0 O O O 0 Unlike Parenchyma Thin flexible l cell walls Alive at maturity Carry out most metabolism within plant Found in leaves Collenchyma Unevenly thickened but exible l cell walls Alive at maturity Supports young growing stems Found in petioles that connects stem to leaves Sclerenchyma Thick rigid 2 cell walls lay down one cell wall and then a much thicker one around that primary wall Dead at maturity Provides support ade up of schlerid or fiber cells Xylem conducts water and minerals from roots I Tubular cells Dead at maturity Tracheids thin tubular cells cell wall contain pits thin regions with only l cell walls 0 Vessel elements short wide tubular cells Phloem conducts organic compounds I Sievetube members conducting cells alive but not many organelles Companion cells nonconducting cells alive and support sievetube members and tissues 1 tissue does not function in Support Gas exchange Nutrient exchange Both gas and nutrient exchange Meristems generate cells for new organs Concept 352 Apical meristems are located at the tips of roots and in the buds of shoots Elongate shoots and roots through primary growth Lateral meristems or cambia run parallel to the long axis of roots and shoots Add thickness to woody plants through secondary growth Overview of Primary amp Secondary Growth Figure 351 Primary pith primary xylem primary phloem cortex epidermis Secondary have additional secondary xylem and phloem and cork cambium adds width Primary growth lengthens roots and shoots Concept 353 Primary Growth of Roots Figure 3513 and 3512 Zones cell division elongation maturation Produces the epidermis ground tissue and vascular tissue O O o Organiz O 0 Root cap covers and protect the apical meristem Soil can be very abrasive root cap cells get torn off and replaced L ateral Roots Arise from the pericycle within the vascular bundle below the endodermis Emerge from the main root Outermost cell layer in the vascular cylinder Figure 3514 Primary Growth of Shoots Shoot apical meristem domeshaped mass of dividing cells at the tip of the terminal bud Responsible for primary growth in young stems increasing the lengt Figure 3515 ation of Primary Tissues Figure 3516 Vascular tissue is arranged in a ring of bundles in gymnosperms and most dicots outermost to innermost Epidermis dermal tissue that protects outer most Cortex ground tissue Phloem point outward Xylem point inward Pith more cortex tissue in the center In most monocots vascular bundles are scattered throughout the ground tissue The vascular bundles of dicots separate the ground tissue into two zones Which of the following correctly describes the arrangement of these zones Outermost cortexphloem xylem pith Tissue organization of Leaves Upper epidermal layer Lower epidermal layer Covering the dermal layer is a waxy cuticle that retains water within the leaf Lower epidermus has openings called stomata for gas exchange 0 ening is controlled by guard cells Center of the leaf is called the mesophyl Pallisade mesophyl photosynthesis tightly packed Spongy mesophyl not tightly packed allows exit of oxygen and entrance of C02 Vascular bundles veins within a leaf Contain xylem and phloem Bundle sheath cells surround them In twenty years time a tree swim hung on a branch will be About the same height growth occurs at tips of branches so the trunkthick branches will not grow Secondary growth adds girth to stems and roots in woody plants Concept 354 Secondary growth occurs in stems and roots of woody plants The secondary plant body consists of tissues produced by the vascular cambium and cork cambium Primary and Secondary Growth of a Stem O O 0 Secondary Growth Structure Layers of periderm Bark Cork Most recent cork cambium Secondary phloem Vascular cambium Secondary xylem Inside these is the primary growth structure Figure 3518 Vascular Cambium Figure 3519 2 types of cells in vascular cambium ring of meristematic actively dividing tissue Fusiform initials Oriented parallel to the axis of the stem or root Produce cells that will make up the xylem and phloem Ray initials Oriented perpendicular to the stem or roots axis u m Produces vascular rays 0 Results of Secondary Growth Figure 3520 I Heartwood older layers of secondary xylem No longer transport water Often clogged with resins In the center ofa log I Sapwood young layers of xylem Still transports water Much smaller than heartwood On the outside of the heartwood I Vascular cambium secondary phloem and corkcork cambium all surround these two xylem a ers o The bark of a tree is made up mainly of I Vascular cambium I Tracheid cells I Phloem o Bark I All the tissues external to the vascular cambium I Secondary phloem and periderm I Cork cambium Gives rise to the secondary plant body39s protective covering or periderm I Lenticels Areas in the periderm where gas exchange with the outside air can occur Ch 36 Wechresday March 12 2008 Ch 36 Transport in Vascular Plants Physical forces drive the transport of materials in plants over a range of distances 0 Transport invascular plants occurs on three scales I Transport of water and solutes by individual cells I Shortdistance transport of substances from cell to cell at the level of tissuesorgans I Longdistance transport within xylem and phloem Overview of Transport in Plants 0 Roots absorb water and minerals 0 Water and minerals moved up in xylem 0 Water lost from leaves by transpiration 0 C02 in 02 out through stomata 0 Sugars transported down through phloem 0 Roots exchange gases Take in 02 and release C02 Selective Permeability of Membranes 0 Plasma membrane controls movement of solutes into and out of the cell I Passive transport movement across the membrane down a concentration gradient doesn39t require energy I Active transport pumping of solutes across the membrane against their concentration gradient requires energy I Transport proteins integral membrane proteins that carry out transport 0 Proteins with open channels that allow passive transport 0 Specialized proteins use ATP for active transport 0 Proton Pumps I Membrane proteins that actively transport H ions across plasma membrane I Create a H gradient that is a form of potential energy I Helps produce a voltage known as a membrane potential 0 Voltage different provides potential energy to do work I Figure 363 o Solute Transport in Plant Cells I Figure 364 I Transport of many solutes driven by proton gradients I Cotransporters transport proteins couple passage of one solute with the passage of another usually coupled with H o Uptake of N03 0 Uptake of sucrose 0 Happens with ions against membrane voltage and neutral solutes against concentration gradient 0 Effects of Differences in Water Potential I Osmosis the diffusion of water across a selectively permeable membrane 0 Affected by solute concentration and pressure I Factors Affecting Water Potential 0 Water potential Lp affected by o Solute potential Lps proportional to concentration of dissolved molecules 0 Pressure potential Lpp physical pressure on a solution 0 LPS W w I Analysis of Water Potential 0 Figure 365 o Solute added to one side decreases solute potential creating a low water potentital 0 Water ows from high potential to low potential pure water to solution 0 Adding pressure to the solution will create an increase in pressure potential and evens out the water potential 0 Water does not move 0 Adding even more pressure to the solute will create a higher pressure potential and higher water potential 0 Water ows from solution to pure water 0 Exert negative pressure on pure water decreasing the pressure potential 0 Causes water to ow from solution to pure water I Water Potential in Plant Cells 0 Figure 366 Cell has a negative water potential because it contains solute neg solute potential 0 Cell in distilled water will take in water because the solutes in the cell cause the water potential to be lower in the cell that outside of it 0 Cell in hypertonic solution will lose water because the solute potential of the solution lowers the water potential of the solution 0 Figure 367 I If Lpp03 MPa and Lps 045 MPa the resulting Lp is o 03 045 015 MPa I The value for Lp in root tissue was found to be 0 15 MPa Ifyou take the root tissue and place it in a 01 M sucrose solution LIP023 net water ow would be 0 From the tissue to the sucrose solution 0 Maj or Compartments in Vacuolated Plant Cells 0 Figure 368a 0 Cell wall I Plasmodesmata connection of cytoplasm of adjacent cells I Plasma membrane controls traffice of molecules between cell wall and the cytosol o Cytosol o Vacuole I Vacuolar membrane tonoplast regulates transport between cytosol and vacuole 0 Transport Routes Between Cells 0 In most plants tissues in the cell walls and cytosol are continuous from cell to cell I Cytoplasmic continuum sym plast movement is through plasmodesmota never crosses cell membrane I Continuum of cell walls and extracellular spaces apoplasts travels through cell wa I Figure 368 0 Roots absorb water and minerals from the soil Concept 362 0 Water and minerals from the soil enter the plant through the epidermis of the roots and ultimately ow to the shoot system 0 Lateral Transport in Roots Figure 369 Root hairs increase surface to increase contact Vascular cylinder is surrounded be endodermis Water minerals get to the cycliner by apoplastic routes or symplastic route 0 Go through epidermis cortex endodermis 0 Can be exchange between the two routes Casparian strip waxy waterproof strip in the endodermis water cannot get into the vascular cylinder through the apoplastic route 0 Water and minerals ascent from roots to shoots through xylem o Xylem sap water and minerals rises to heights of more than 100 m in the tallest plants 0 Pushing xylem sap Root Pressure I At night when transpiration is low root cells still pump ions into the xylem of the vascular cylinder 0 Lowers water potential and water ows into the root cortex generating root pressure I Sometimes causes guttation in small herbaceous plants forces water out of leaves I Root pressure can transport water only over small distances 0 How does water make it from the soil to the leaves in tall trees during the day I Pulled up from the leaves 0 Pulling Xylem Sap I The Transpirationcohesiontension mechanism 0 Water is pulled upward over great distances by negative pressure tension in the xylem I Transpirational Pull Figure 3612 0 Transpiration the evaporative loss of water from the leaves of a plant 0 Water vapor in the air spaces of a leaf diffuses down its water potential gradient and exits the leaf via stomata 0 Less water is left in the mesophyl and water is pulled out of the xylem to bring equillbrium o This produces negative pressure in the leaf which is transmitted to water in the xylem o Cohesion and Adhesion Figure 3613 I The transpirational pull is transmitted all the way from the leaves to the root tips and even into the soil 0 Lowest water potential in outside air and highest in the soil I Facilitated by cohesion and adhesion o Cohesion water molecules are attracted to one another making long continuous chains 0 Negatively charges oxygen forms hydrogen bonds with positively charged hydrogen atoms keeping the water molecules together 0 Adhesion water molecules stick to the sides of the xylem cells 0 Made of cellulose which is polar covalent and water molecules adhere to it o Prevents water from moving back down the xylem due to gravity 0 Stomata help regulate the rate of transpiration Concept 364 o The large surface area of leaves increases photosynthesis but also increases water loss through stomata also allows for entrance of C02 0 Stomata Major Pathways from Water Loss Figure 36 15a I About 90 of water loss by plant occurs through the stomata I Water loss is regulated by guard cells that ank the stomata I Guard Cells 0 Flank the opening 0 Can change shape to keep stoma open or closed with turgor pressure depending on the moisture in the climate I Opening and Closing Stomata Figure 36 15b 0 The transport of K is coupled with H pumps 0 H is pumped out setting up a membrane potential 0 K moves into the cell following the membrane potential gradient 0 K entrance decreases the water potential so water enters cell and creates turgor pressure opening the stomata 0 Organic nutrients are translocated through the phloem Concept 365 o Translocation the transport of organic nutrients in the phloem of a plant 0 Movement from Sugar Sources to Sugar Sinks I Phloem sap is an aqueous solution that is mostly sucrose I Sugar source plant organ that is a net producer or source of sugar ie mature leaves 0 Leaves are not a source but a sink in the spring when they are just developing I Sugar sink plant organ that is a net consumer or storage site of sugar ie tuber or bulb during the growing season 0 Loading Sucrose into Phloem Figure 3617 I Proton pumping and cotransport of sucrose allows companion cells to accumulate sugar at high concentrations I Sugar is transported from one mesophyl to another through the symplast and some moves out through the apoplast into the companion cells and ultimately the sieve tube member 0 The active transport of the apoplastic route allow for higher concentrations of sucrose than could be reached with only symplastic 0 Pressure Flow Figure 3618 I High pressure at source I Low pressure at sink I Pressure gradient drives ow of phloem sap from source to sink I Sugar is loaded into sieve tube which lowers water potential water follows by osmosis I Water uptake causes positive pressure I Unloading of sugar at sink reduces pressure 0 Which of the following doe not appear to involve active transport across membranes I The movement of water into the vascular cylinder of a root osmosis caused by transpiration from the leaves 0 Water inside all of the xylem cells is being pulled upward primarily by 0 Water tension 0 Ch 3 7 Monday March 24 2008 a It 16 AM 0 Ch 37 Plant Nutrition 0 Where did the most of the biomass of a large tree come from 0 Air C02 is the carbon source for the organic sugars produced by photosynthesis Plants require certain chemical elements to complete their life cycle Concept 371 0 Plants derive most of their organic mass biomass from the C02 in the air 0 Also need soil nutrients like water and minerals 0 Figure 371 I Roots take in water and minerals from the soil I Roots take in 02 and expel C02 I C02 from photosynthesis diffuses into leaves through stomata I Water and 02 leave through stomata 0 Essential Plant Elements I Table 371 Memorize which ones are macro or micro for test not function I Essential element element required by a plant to complete its life cycle 0 Macronutrients required by plants in relatively large amounts 0 ie C02 which is needed at 90 mass tissue 0 Micronutrients required in only small amounts 0 Function mainly as cofactors in chemical reactions 0 Soil quality is a major determinant of plant distribution and growth Concept 372 o In addition to climate texture and composition of soil are major factors determining the distribution of plants 0 Texture and Composition of Soils I Soil is made up of particles derived from the breakdown of rocks minerals along with organic material humus I Texture the relative amounts of various sized soil paiticles o ie small grained large grained mixture I Composition relative amounts of inorganic and organic components 0 Soil Horizons I Figure 375 I Soil horizons are visible in verticle pro le I quotAquot horizon is a mix of humus and mineral I Humus consists of decomposing organic material Prevents packing of smaller mineral particles amp allows retention of water Soil Horizon Layers o A organic rich and claypoor zone weathered ground 0 Attracts water for plants growing within it B clayrich zone also enriched in iron oxides C zone barely altered from pristine rock source of minerals for B and A horizons o D unaltered rock 0 Availability of Water I Figure 376a I After rains smaller spaces in the soil retain water because of Hbonding with clay and other paiticles I Film of looselybound water is available to plant roots I Not all the soil water can be extracted by the plant 0 Availability of Mineral Ions Figure 376b Many cations are attracted to negatively charged soil particles Cation exchange is a process that contributes to their uptake 0 Plant decrease the pH of the soil uid 0 T H s in the uid are exchanged for the mineral cations bound to the soil particles 0 Leaching Removal of nutrients from soil by water that percolates through it 0 Most pronounced in sandy soils most leaching o Clays are best at holding onto nutrients least leaching Sand is made up of larger particles silt is made up of moderatesized particles and clay is made up of small particles 0 Large particles create larger pores and easier for water to move through and more leaching of nutrients o Smaller particles can pack in more tightly created much smaller pores and waternutrients are retained better Which soil mineral is most likely leached away during a hard rain 0 N lJr o Kl o Ca o N 0339 negatively charged soil particles are negatively charged so positively charged particles will stick to them but negatively charged minerals will not 0 Nitrogen is often the mineral that has greatest effect on plant growth Concept 373 0 Limiting nutrient relative availability in environment is less that plants need for it o Nitrogen is used as a component 0 Proteins Nucleic acids Chlorophyll Others 0 Soil Bacteria amp Nitrogen Availability Figure 379 Nitrogen xation bacteria convert N2 from the atmosphere to NH3 Ammoni cation bacteria convert N39 containing organic material to NH4 Nitri cation bacteria convert NHfr to NO form that can be used by plants Denitri cation bacteria convert N0339 to N2 back into the atmosphere to continue c cle 0 Plant nutritional adaptations often involve relationships with other organisms Concept 374 0 Two examples of plants with mutualistic relationships with other organisms Symbiotic nitrogen xation Mycorrhizae o Bacteria amp Symbiotic Nitrogen Fixation Symbiotic relationships with nitrogen xing bacteria provide some plants with a builtin source of xed nitrogen Root nodules swellings along the root that have been quotinfectedquot by Rhizobium bacteria 0 Figure 3710a Inside each nodule Rhizobium bacteria assume a form called bacteroids which are contained within vesicles formed by the root cell 0 Figure 37lOb Rhizobium convert N2 into ammonium NH4 The plant provides a low02 environment for the Nfixation process 0 Thick cell walls 0 Leghemoglobin binds up oxygen to keep it away from the nitrogen fixing bacteria in the root nodules 0 Root Nodules on Legumes oooum O O O O I Figure 3711 0 Chemical signals sent between root and bacteria 0 Bacteria move into the cortex form bacteroids stimulate growth of cortex and pericycle cells 2 cell masses fuse forming a nodule Nodule develops vascular tissue transports ammonia to plants and carbohydrates to bacteria The function of a root nodule39s leghemoglobin is to I Regulate the supply of oxygen to Rhizobium A woodlot is sprayed with a fungicide What would be the most serious effect of such spraying I A decrease in tree growth due to the death of mycorrhizae Mycorrhizae amp Plant Nutrition I Mycorrhiz ae mutualistic relationship between soil fungi and plant roots 0 Figure Fungus gets a steady supply of sugar from the plant Fungus provides additional water and nutrients for host plant Two Types of Mycorrhizae Figure 3712 0 Ectomycorrhiz ae fungi remain outside of the plantroot cells 0 The mycelium of the fungus forms a dense sheath mantle over the surface of the root 0 Endomycorrhizae penetrate into the root cells but do not go into the plasma membrane 0 Some form densely branched structure call arbuscules 0 Found in over 85 of plant species Epiphytes Parasitic Plants amp Carnivorous Plants I Figure 3713 I Draw nutrients from nontypical sources I Epophytes grow on other plants not taking any resources from that plant only from the air 0 6m Parasitic draw resources water and nutrients from the host plant mistletoe o Harmful to host plant 0 Some are photosynthetic and some are not 0 Nutquot quotquothasnoquot 39 carbohydrates too I Carnivorous plants that eat animals need animals as nitrogen source 0 Venus y trap found in nitrogen poor soils draw not only nutrients but All soil well suited for the growth of most plants would have all of the following properties except 0 OOO Abundant humus Air spaces High cation exchange capacity High pH basic need hydrogen ions for cation exchange basic soil would take up the hydrogen ions Ch 38 Friday March 38 2008 950 y Ch 38 Angiosperm Reproduction Most of the plants used commercially are angiosperms Pollination enable gametes to come together within a ower Concept 381 In angiosperms the dominant sporophyte diploid produces spores that develop into male gametophytes pollen grains and female gametophytes embryo sacs Simpli ed Angiosperrn Life Cycle Dominant sporophyte give rise to reproductive owers Male stamens produce pollen grains Female ovary produces egg Pollen fertilized egg producing zygote O O I Figure 382b I Embryo 0 Flower Structure I Flowers are the reproductive shoots of the angiosperm sporophyte I There are 4 oral organs in a complete ower Figure 382a Sepals leaves that protect the ower before it blooms can be green and photosynthetic or colored like the petals Petals brightly colored to attract pollinators to the owers Stamens male reproductive organs 0 Filament o Anthers where pollen grains are produced Carpels female reproductive organ 0 Stigma where pollen grain lands 0 Style grain germinates through this long stem 0 Ovary where grain fertilizes egg I Incomplete owers lack l or more of the oral organs I Variations in Floral Structure Figure 383 Bilateral symmetry single plane through which to cut the ower in two equal halves o Orchid Radial symmetry identical along several planes 0 Daffodil Superior ovary has the stamens attached bellow ovary Semiinferior ovary stamens half way up Inferior stamen attaches above ovary Lupine in orescence multiple owers at the end of a shoot Sun ower in orescence every petal is an individual specialized ower in the center there are tiny ower specialized for reproduction I Reproductive Variations Figure 383 Incomplete owers may lack either stamens or carpels o Staminate owers do not have carpels do not produce eggs 0 Carpellate owers do not have stamens do not produce pollen Plants with owers of both sexes are monoeocious o Maizecorn Plant that have owers of one sex of the other are dioecois o Arrowhead one plant is male and another is female 0 Meiosis occurs within all the following ower parts except the 1 Style I Megasporangium o Staminate owers Produce pollen Are complete Can develop into fruits Are found only on dioecious plants 0 Pollen The Male Gametophyte I Figure 384 I Each microsporangia contains diploid microsporocytes microspore mother cells I Microsporocytes divide by meiosis to produce haploid microspores I Microspore undergoes mitosis to make 2 cells 0 Generative cell what will form the sperm 0 Tube cell germinate when it fertilizes an egg and forms a tube for generative cell to follow I Pollen grain becomes the mature male gametophyte o Embryo Sac The Female Gametophyte I Figure 384 I Megasporangium contains megasporocyte megaspore mother cells I Megasporocyte undergoes meiosis producing four haploid megaspores only one survives I Megaspore that survives undergoes 3 rounds of mitosis to form the embryo sac o Antipodal cells 3 haploid o 1 large cell made up of 2 polar nuclei both haploid o Synergids 2 that ank the opening of the egg cell Egg 1 o Pollination and Fertilization I Pollination occurs when a pollen grain lands on the sticky stigma of a compatible plant 0 Dispersed by animalswind I Pollination does not necessarily lead to fertilization I Fertilization sperm delivered to egg cell and endosperm in ovule 0 Polar nuclei and one sperm become triploid endosperm o Other sperm and egg become embryo o Mechanisms Preventing Self Fertilization inbreeding is bad because leads to disorders I Dioecious plants I Flower morphologydevelopment 0 Figure 387 pin and thrum ower I Selfincompatibility the ability of a plant to reject its own pollen o Regulated by alleles of Sgenes 0 Genes attack cells that are their own and not ones from a different individual 0 Gametophytic stigma and style test proteins on the pollentube surface 0 Alleles that are expressed by growing pollen grain and are tested by the female plant if they match to closely it is rejected 0 Sporophytic proteins are on the surface of the pollen grain 0 When grain lands on stigma of the ower and the genes match to closely it is rejected I Aplant that is sporophytic selfincompatible has a genotype Sssg for the S locus It receives pollen from a plant that is S3S9 Which of the following is most likely to occur 0 None of the pollen will germinate the matching 9 allele will prevent germination o Sporophyte incompatibility so both alleles are taken into account 0 If it was gametophytic then half of the pollen would germinate 0 After fertilization ovules develop into seeds and ovaries intro fruits Concept 382 0 Double Fertilization I Figure 386 I If pollen grain germinates a pollen tube grows down the style toward the ovary I The pollen tube discharges two sperm into the female gametophyte embryo sac within an ovule I One sperm fertilizes the egg forming the zygote I Other sperm combines with two polar nuclei of the embryo sac39s large central cell forming a triploid cell that develops into the nutritive tissue called endosperm I Unique to angiosperrns 0 From Ovule to Seed I Integuments of ovule develop into seed coat outer coating of seed I Triploid endosperm cell divides to form endosperm that absorbs nutrients from the parent plant I Zygote develops into an embryo new sporophyte stage of plant 0 Beginnings of cotyledon can be seen in embryo o Endosperm Development I In most monocots and some dicots the endosperm stores nutrients that can be used by the seedling after germination I In other dicots the food reserves of the endosperm are exported to the cotyledons o Absorb nutrients prior to germination 0 After germination seedling draws nutrients from cotyledons o Embryo Development I Figure 387 I Zygote fertilized egg cell 0 Undergoes one division 0 Terminal cell becomes o Basal cell becomes anchor called the suspensor 0 Seed Structure I Figure 388 I Dicots o Hypocotyl part below where the cotyledons attach o Epicotyl where cotyledons attach o Radicle 0 Two thick cotyledons 0 Garden bean 0 Two eshy parts of seed are cotyledons what you eat when eating beans 0 Embryo draws nutrients from cotyledons after germination I Other Dicots 0 Similar strucures but think cotyledons o Cator bean o Sead coat endosperm cotyledons epictole hypocotyl radicle I Monocot 0 Single cotyledon scutellum o Coleoptile surround the early embryo as it begins to sprout shoot end 0 Coleorhiza surrounds early embryo as it begins to sprout root end 0 From Ovary to Fruit I Figure 389 Afruit develops from the ovary of the ower 0 Ovary thickens with chemical signals Protects enclosed seeds and aids in dispersal by wind or animals Simple fruit 0 Flower just has a single ower and ovary where fruit develops around seeds 0 Pea plant Aggregate fruit 0 Flowers have multiple carpel that develop into fruitlets that merge together to form one fruit 0 Raspbe Fruit Multiple fruit 0 Develop from in orescences owers that have multiple owers at end of stem 0 Each ower forms a fruit that merge together to form one 0 Pineapple 0 From Seed to Seedling I A mature seed dehydrates and enters a dormancy phase 0 Helps ensure that seed germinated at a time and place most advantageous to the seedling 0 Breaking dormancy often requires environmental cues like temperature or water availability I Germination depends on imbibing or uptake of water 0 Three identical plates of radish seeds are incubated under three conditions with results as shown Their DRY weights in increasing order will be I 3 no light water 1 light no water 2 light water I 2 is able to photosynthesize and grow normally I 3 germinated by could no photosynthesize so could only use endosperm for nutrients I l more biomass in seeds but just hasn39t germinated 0 Protection of the Apical Meristerns I Emerging roots and shoots must push through the soil without abrading the apical meristems at their ti s I Root apical meristernsis protected by a coleorhiza monocots or root cap I Shoot apical meristem is protected by either 0 A coleoptile sheath enclosing the shoot tip of monocots o A hypocotyle hook pulls shoot tip out of the soil by bending the stem through the soil 0 Two Types of Seed Germination I Figure 3810 I Common Garden Bean dicot o Radicle emerges rst 0 Hypocotyle is closest to soil surface and pulls the coltyledon out of the soil which develops into foliage leaves I Maize monocot o Radicle emerges rst 0 Coleoptile pushes up through soil and opens up to produce foliage leaves 0 Which of the following is not true of the hypocotyl hook I In is the region just below the cotyledons I It straightens when exposed to light I It is the rst structure to emerge from a dicot seed the radicleembryonic root emerges rst I It pulls the coltyledons up through the soil 0 Many owering plants clone themselves by asexual reproduction Concept 383 o Mechanisms of Asexual Reproduction I Fragmentation 0 Separation of parent plant into parts that develop into whole plants I Apomixis o Asexual production of seeds 0 Diploid cell in ovule gives rise to embryo o Vegetative Propagation and Agriculture I Humans have devised various methods for asexual propogation of angiosperms I Clones from cuttings 0 Plant that are asexually reproduced from plant fragments pick favorable ones I Grafting m o A twig or bud from one plant is grafted onto a closely related species or a different variety of the same species 0 Replicates favorable traits of parent that donated graft o Seedless varieties of fruits are done this way seedless grapes Double fertilization in plants is the union of o 1 sperm to 1 egg and 1 sperm to the polar nuclei Ch 40 Wednesday April 02 2 108 941 AlVl Ch 40 Basic Principles ofAnimal Form and Function 0 Physical laws and the environment constrain animal size and shape Concept 40 l I Physical laws especially the physics of exchanging materials with the environment limit the range of animal forms I Evolutionary Convergence 0 Different species39 independent adaptation to a similar environmental challenge 0 ie Fusiform tapered on both ends shape in fastswimming aquatic anima s 0 Figure 402 I Exchange in Simple Organisms Figure 403 o Singlecelled organisms 0 Exchange material by diffusion o Entire plasma membrane is exposed to medium 0 Multicellular organisms with a sac body plan 0 Body wall is only 2 celllayers thick 0 Exchange is by diffusion I Exchange in Complex Animals 0 Large complex animals have highly folded or branches intemal surfaces specialized for exchanging materials 0 The increases surface area allows for more diffusion of materials such as carbon dioxide and oxygen 0 Figure 404 0 Animal form and function are correlated at all levels of organization Concept 402 I Cell animals fundamental unit of structure and nction I Tissues groups of cells within a common structure and function 0 Epithelial Tissue 0 Covers the outside of the body and lines the organs and cavities within the body 0 Cells are closely joined 0 Figure 405 Strati ed several layers of cells Simple single layer of column shaped cells Pseudostrati ed ciliated single column of cells Cuboidal box shaped cells lining the tubules in the kidneys I Sqaumous tilelike cells blood vessels amp alveoli of lungs very thin Strati ed squamous multiple layers of at cells skin oldest cells on the top sometimes dead 0 Connective Tissues O I 0 Energy 0 Functions mainly to bind and support other tissues 0 Composed of sparsely packed cells scattered throughout an extracellular matrix 0 Major types Figure 405 I Loose connective tissue composed of individual cells that secrete collagen bers very tough and elastic bers that make it stretchy Adipose storage site for lipids and provides paddinginsulation Fibrous connective tendons and ligaments very tightly capped collagen bers Cartilage embryos in between joints ear nose more exible than bones and provide shock absorption Bone connective tissue living cells dispersed throughout Blood scatted cells with an extracellular matrix 0 Muscle Tissue o Composed of long cells called muscle bers capable of contracting in response to nerve signa s 3 types Figure 405 I Skeletal allow for movement under voluntary control Cardiac makes up the heart involuntary contro I Smooth lines the digestive tract and blood vessels involuntary Nervous Tissue 0 Sense stimuli and transmits signals throughout the animal 0 Nerve cell responsible for receiving and transmitting is the neuron Figure 405 Transmit electrical signal down axon Organs a specialized center of body function composed of several different types of body tissues In all but the simplest animals different tissues are organized in organs 0 Figure 406 Organ system a groups of organs working together in performing vital body functions Organ systems carry out the major body functions of most animals 0 Table 40l Different organ systems Organism groups of organ systems working together 0 Animals use chemical energy in food to sustain form and function Concept 403 Bioenergetics the ow of energy through an animal Input 0 Resource food goes in Metabolism and Synthesis exergonic Output 0 Release of heat Waste feces and urine 0 Growth repair defense storage reproduction Source amp Allocation Figure 407 Animals harvest chemical energy from food Energy containing molecules are broken down to make ATP Once energetic needs are met remaining molecules are used in biosynthesis Figure 407 Organic molecules in food gt Digestion and absorption gt nutrient molecules gt cellular respiration or carbon skeletons gt ATP gt workbiosynthesis o Quantifying Energy Use I Metabolic rate the amount of energy an animal uses in a unit of time I Can be measured by the amount of oxygen consumes or carbon dioxide produced by an organism I Figure 408 0 Size amp Metabolic Rate I The relative metabolic rate metabolic rate per gram is inversely related to body size among similar animals 0 Metabolic rate is high for smaller animals I Figure 4010 0 Reptiles have much lower metabolic rates because they are ectothermic o Regulates temperature through the environment so has much lower metabolic rate 0 Mammals and birds are endothermic 0 As they get larger there is less surface to volume ratio so need less energy to regulate body temperature 0 Activity and Metabolic Rate I Basal metabolic rate BMR metabolic rate of an endotherm at rest 0 Maintain a constant body temperature I Standard metabolic rate SMR metabolic rate of an ectotherm at rest 0 Body temp can change with environment 0 Must measure it at a standard temperature to make comparisons I Comparing basal and standard metabolic rates 0 Human 12 kcalmin o Alligator 004 kcalmin I Figure 409 o Endotherms can maintain higher levels of activity for a longer period of time because their metabolic rate is higher than ectoderms I When is the best time to measure basal metabolic rate 0 At rest prior to its first meal of the day I A mouse and a lizard with the same body mass were placed in experimental chambers and their metabolic rates were measured over a range of temperatures From the data shown which were collected from the mouse and which from the lizard o A mouse higher metabolic rate endotherm really high at low temp because it needs to maintain the high constant body temp o B lizard body temp varies with external temp so at the low temp it has a low metabolic rate 0 Animals regulate their intemal environment within relatively narrow limits Concept 404 0 Interstitial fluid uid that lls the spaces between cells Intemal environment I Exchange occurs with cells here across plasma membrane and cell 0 Homeostasis maintaining internal variable within an acceptable range 0 Regulating amp Conforming I Regulator animal that uses internal control mechanisms to moderate intemal change in the face of external uctuation Conform er animal that allows its internal conditions to vary with certain external changes Internal temp increases with external temp and internal salinity remains constant with increased external salinity graph 0 Osmoregulator and thermal conformer o Ectothermic organism because it conforms with temperature 0 Mechanisms of Homeostasis I Homeostatic control systems have three functional components Receptor something to tell if there is a change in a variable stimuli Control Center something that sends out a signal to moderate the change Effector prevents the change from occuring brings it back to a set point 0 Analogy Thermostat Figure 4011 I Negative Feedback 0 Response to change is to counteract the change resulting in a return to the original condition 0 quotNegativequot because it negates the initial change 0 Figure 4021 0 Body temperature is about 986 degrees 0 If body gets hotter than that nervous system sends signal to the brain which releases hormones I Sweat glands in skin begin to produce sweat in response I Dilates blood vessels near the skin bringing warm blood to the surface I These cool the body and bring the temperature back to the homeostatic level 0 If body get cold hypothalamus sends signals to constrict blood vessels in the skin to keep warm blood inside I Causes muscles to twitch and energy expended releases heat and raise temp I Positive Feedback 0 Intensives the original change when the need exists 0 Drives events to a conclusion 0 Tends to be selflimiting 0 Example Child Birth 0 When the fetus is ready to be born it exerts pressure on stretch receptors 0 Send signal to hypothalamus in brain which releases hormone oxytocin 0 Causes contractions o Fetus pushes more on receptors and the cycle begins again I Which of the following is an example of a negative feedback response 0 Meerkats bask in the sun at the beginning of the day but avoid it during the heat of the day 0 Thermoregulation contributes to homeostasis Concept 405 0 Thermoregulation the process by which animals maintain an internal temperature within a tolerable range Ectotherms animals that use environmental energy and behavioral adaptation to regulate body temperature I quotCold bloodedquot I Ectotherms include most inverterbrates sh amphibians and nonbird reptiles I They tolerate a greater variation in internal temperature I Lower metabolic rates can make it past times with little food by hybernating Endotherms animals that use metabolic heat to regulate body temperature I quotWarm bloodedquot I Endotherms include birds and mammals I More energetically expensive but enable them to maintain a high level of aerobic metabolism I Higher metabolic rates need food I Can maintain a higher level of activity I Figure 4012 Modes of Heat Exchange Figure 4013 I m I Radiation emission of electromagnetic waves by all object warmer than absolute zero sunlight I Evaporation the removal of heat from the surface of a liquid that is losing some of its molecules as gas sweating I Convection transfer of heat by the movement of air or liquid past a surface I Conduction the transfer of heat between molecules of object in direct contact 0 Balancing Heat Loss amp Gain I Insulation reduces the ow of heat between an animal and its environment 0 Includes feathers fur bladder skin 0 Figure 4014 I Circulation adaptations Figure 4016 0 Vasodilation blood ow in the skin increases facilitating heat loss 0 Vasoconstriction blood ow in the skin decreases lowering heat loss I Counter current exchange Figure 4015 0 Mostly in aquatic organisms 0 Heat is exchanges between different parts of the circulatory system 0 Arteries are very close to the veins and they exchange heat arteries coming from heart will be warmer than the veins coming from the skin in the cold water 0 Cooling by Evaporative Heat Loss I Sweating causes the loss of heat by the evaporation of water from the skin 0 Humans I Panting causes heat loss through exhalation of water vapor o ogs I Bathing moistens the skin 0 Elephants o Other Behavioral Responses I Basking in the sun and moving into the shade I Maintaining a certain posture o Dragonfly can lay parallel with ground lays out absorbing heat from sunlight or perpendicular orientation decreases surface area exposed to sunlight and decreases body temp o For which of the following animals would the percent of its energy budget spent for homeostatic control be the largest I An arctic bird endotherms in extremely cold conditions 0 Which of the following is the correct sequence involved in the regulation of homeostasis I Stimulusreceptorcontrolcentereffectorresponds 0 Which of the following processes is able to move heat in one direction only away from the body I Evaporation Ch 41 Monday April 07 ZUUX 948 AM Ch 41 Animal Nutrition Homeostatic mechanisms manage an animals energy budget Concept 411 o Glucose regulation as an example of homeostasis I Glucose is a major fuel for cells I Its metabolism is regulated by hormone action I Figure 413 c When blood glucose levels rise the pancreas secretes insulin 0 Insulin enhances the transport of glucose into cells amp stimulates the liver and muscles to store glucose as glycogen c When blood glucose levels drop the pancreas secretes glucagon o Glucagon promotes the breakdown of glycogen in the liver amp release of glucose into the blood 0 Appetite Regulating Hormones I A variety of hormones regulate appetite by acting on the feeding control center in the hypothalamus I Stimulated by ghrelin in the stomach released into the blood stream stimulating our appetite o Ghrelin stimulated by the smell of food I Suppressed by leptin peptide YY PYY amp insulin I Leptin is secreted by adipose tissue 0 Body fat decreases gt little leptingt appetite increases 0 Makes it hard for people to lose weight 0 Body fat increases gt much leptingt appetite decreases 0 An Animal s Diet must supple Carbon Skeleton and Essential Nutrients 0 Carbon skeletons are mostly supplied by carbohydrates proteins amp lipids o Other nutrients include the vitamins and minerals I Substances that help catalyze reactions and others that are needed in smaller quantities but still essential to our diet 0 Individuals whose diet consists primarily of beans would likely become I Malnourished may be taking in enough calories but they don t have all of the essential nutrients needed for a complete diet 0 Essential Nutrients I Essential amino acids are ones that animals can t synthesize I Animals require 20 amino acids 0 Complete proteins have all 20 amino acids 0 Incompletely proteins don t have all 20 c Figure 4110 I Essential fatty acids are required in the diet 0 Usually unsaturated fatty acids 0 From vegetables 0 Human need linoleic acid 0 Vitamins I Vitamins are organic molecules I Serve as antioxidants and coenzymes not for energy I WaterSoluble dissolve in water 0 When in excess will be secreted through urine I FatSoluble stored in fatty tissues 0 Excess of these vitamins are stored and can become toxic at high levels I Table 411 0 Know which ones are watersoluble and which ones are fatsoluble 0 Minerals I Minerals are inorganic elements or compounds in the diet I Part of biological molecules but do not serve as energy 0 Iron transports oxygen 0 Calcium muscle contractions I Table 412 The Main Stages of Food Processing are Ingestion Digestion Absorption and Elimination Concept 413 0 Four Stages of Food Processing I Ingestion food brought in through the mouth I Digestion 0 Mechanical breakdown physical breakdown of food grinding by teeth 0 Chemical breakdown digestive chemicals amp enzymes breakdown food polymers to monomers I Absorption small subunits transported out of digestive system into the rest of the body I Elimination indigestible material expelled from body 0 Not all food can be digested I Figure 4112 0 Intercellular Digestions I Sponges are sedentary lter feeders with no specialized digestive system I Digestion takes place in collar cells lining waterfilled spongocoel intercellular digestion I Figure 0 Water carrying food particles enter pores 0 Food particles are ltered by collar cells 0 Food enters cell by endocytosis 0 Food digested by collar cells I Limits the size of the food must be microscopic so that an individual cell can ingest it 0 Which of the following possesses a gastrovascular cavity digestive system with a single opening I Platyhelminthes o Extracellular Digestion I Hydra cnidarian have a gastrovascular cavity Opening acts as both mouth and anus Gland cells release enzymes and break down food Nutritive cells absorb nutrients and food particles Indigestible material expelled out mouth Can take in larger food particles better than intracellular but is still not very ef cient limits the time must expel meal before taking in another 0 Figure 4113 0 Digestion in a Tube is More Ef cient I Alimentary canal complete digestive tract that has digestive tube with a mouth and anus I Digestive tube can be organized into specialized regions I Allows animals to eat more frequently I Figure 4114 c Earthworm annelid o Grasshopper arthropod 0 Bird reptile Each Organ of the Mammalian Digestive System has specialized Food Processing Functions Concept 414 0 Major Organs Figure 4115 I Mouth I Pharynx in the throat I Esophagus tube that brings food down to the stomach I Stomach I Small intestine I Large intestine I Rectum I Anus o Accessory Organs I Salivary glands o Secrete saliva I Liver o Secrete bile I Gallbladder 0 Stores amp concentrates bile I Pancreas o Secretes digestive enzymes 0 The Oral Cavity Pharynx amp Esophagus I Mechanical and chemical breakdown of food begins in the mouth I Chewing causes the mechanical breakdown of food by teeth I Salivary glands produce saliva to start chemical breakdown of food 0 Functions of Saliva I Contains amylase breakdowns starches into small polysaccharides and disaccharides I Contains bacteriakilling enzymes and antibodies 0 Makes sure the food is not infected with harmful bacteria I Lubricates food helps with swallowing o Composed of water I Carries food molecules to taste buds on tongue for food quality identi cation 0 From Mouth to Stomach I Figure 4116 I Tongue pushed food into the pharynx initiating swallowing re ex I Larynx moves up amp tips epiglottis over the glottis covering the trachea or air wa Esophageal sphincter relaxes allowing bolus to enter the esophagus Waves of muscular contraction peristalsis moves the bolus down the esophagus to the stomach o Involuntary contraction o The Stomach I The stomach has three major functions 0 Food storage and gradual release into the small intestine 0 Mechanical breakdown of food by using churning contractions o Increases the surface area of the food particles so that enzymes can break them down faster 0 Chemical food breakdown by stomach gland o Acids and digestive enzymes are secreted by gland and break down the large molecules into smaller subunits I Stomach Secretions Figure 4117 HCl 0 Makes stomach uid very acidic o Secreted by parietal cells Pepsinogen o Secreted by chief cells 0 Inactive enzyme that is converted into active pepsin when exposed to HCl 0 Pepsin breaks down large proteins into small peptides Mucus o Protects stomach wall epithelium from acid 0 Secreted by mucus cells I Which of the following components of a hamburger would leave the stomach undigested Starch starts to be broken down in mouth Proteins stomach breaks down proteins Disaccharides and Lipids o The Small Intestine I A narrow tube about 6 m long I Most digestion occurs in the small intestine I Figure 4119 I Intestinal Secretions Some small intestines cells secrete enzymes that complete the digestive process 0 Disaccharides I Breakdown disaccharides into monosaccharides o Dipeptidases carboxypeptidases aminopeptidases I Complete breakdown of peptides into amino acids 0 Nucelotidases nucleosidases phophatases I Breakdown of nucleic acids into sugars nitrogenous bases and phosphates o Pancreatic Enzymes I The pancreas secretes pancreatic juice which is released into the small intestine I Pancreatic juice consists of Water Sodium bicarbodnate o Neutralizes acid to make it more basic ph 78 so that other enzymes can begin to work in the small intestine Amylases Trypsin chymotrypsin carboxynpeptidases 0 Figure 4120 0 Trypsinogen is the inactive form of trypsin o Membranebound enteropeptidase causes the change to the active trypsin form Nucleases Lipases 0 Fat Digestion I Liver produces bile I Bile is stored in the gallbladder then secreted into the small intestine I Bile emulsifies fat breaks them into smaller droplets I This gives enzymes greater surface area to work on 0 Overview of the Enzymes what they break down and where they are released Figure 4121 0 Absorption of Nutrients I Figure 4123 I The small intestine is well adapted for absorption of nutrients I Surface area in increased by numerous fold with fingerlike projections villi and microvilli Into the Blood I Amino acids sugars amp components of nucleic acids pass through the epithelium of the small intestine and enter the blood stream through small capillaries that line the villi of the epithelium 0 Fat Absorption I Figure 4124 Large fat globules are emulsi ed by bile silts Lipases digest fat into monoglycerides and fatty acids Enter intestinal epithelium then are recombines into fats and form chylomicrons transport vesicles for lipids Leave epithelial cells and enter lacteals part of lymphatic system 0 The Large Intestine I Aka the colon I About 15 m long I Absorbs leftover water vitamins and salts I Contains bacteria that consume unabsorbed nutrients and synthesize vitamins I Feces o Transported by peristaltic contraction to the rectum o Rectum expands and stimulates defecation 0 Why does salivary amylase not hydrolyze starch in the small intestine I The low pH in the stomach denatures salivary amylase and pepsin begins hydrolyzing it Evolutionary adaptations of vertebrates digestive systems are often associated with diet Concept 415 0 Dental Adaptations I Carnivore 0 Long pointy canine for biting and killing prey 0 Sharp premolars to cutrip esh o Molars to grind food I Herbivores 0 Don39t need sharp teeth 0 Scissor like incisors to cut up plant matter 0 Big at molars and premolars to grind down plant material I Omnivore o Incisors for cutting vegetable material 0 Some sharp teeth as well 0 Digestion Specializations O oonm I Intestinal length is correlated with diet Because cells walls are dif cult to digest herbivore intestines are long to allow more time for nutrient absorption Carnivore intestines are relatively short because proteins are easy to digest Figure 4127 I Ruminant Digestion Ch 42 Friday April l 2008 3943 A 1 Ruminant animals herbivores that are able to break down cellulose and extract nutrients from tough pant matter Practice rumination regurgitate and rechew food cud Digestive systems house microorganisms which beak down cellulose Figure 4128 Ch 42 Circulation and Gas Exchange Circulatory systems re ect phylogeny Concept 421 0 Transport system functionally connect the organs of exchange with the body cells 0 Figure 421 I Respiratory system lungs maximize the uptake of oxygen and release of carbon dioxide I Exchanged gases at the lungs and at the tissues by way of the circulatory system 0 Gastrovascular I Simple Cavities animals like cnidarians have a body wall only 2 celllayers thick between the external environment amp gastrovascular cavit I Gastrovascular cavity function boy in digestion and circulation I Figure 422 I Platyhelminthes also have gastrovascular cavities o More Complex I Openc 0 Animals Have Two Types of Circulatory Systems irculatory system blood bathes the organs directly Arthropods amp most mollusks Long tube that contracts to move the hemolymph throughout the body heart Don39t empty into closed vessel but into open space in the body hemocoel Hemolymph uid is circulated Figure 423 I Close circulatory system blood is con ned to vessels and is distinct from the interstitial uid Blood con ned to closed vessels that branch down into smaller vessels called capillaries that allows exchange to take place across the walls of the vessels Some invertebrates earthworm and all vertebrates Figure 423 0 I Circulatory System Parts Both of these types of systems have three basic components 0 A circulatory uid blood 0 A set of tubes blood vessels 0 A muscular pump heart 0 Vertebrate Circulatory Systems I Figure 42 1 Tvm chambered hean Fish a Bland circulated rhruugh sysLEmant circulatmn that is pumped hum the ventricles re the all capllanes where it gets uxygen hum the Waist Three chambered hean Amph zuznR phle tmesmal vmebrates u Duuble eueulahuh Pulmueylmeuuspulmunary Eli39ch Fuurehamheredhean Mammalurhiru 42 z u The Mammalian Cardluvasculzr System Figure 42 5 o Capillaries at head and rarelimbs Pulmonary Pulmonary anery artery Cagillaries Capillxries of right lung ol len lung Rignl airium nlgm ventricle Posw nr Aorta vena cava Capillaries oi abdominal organs and hind limbs Right amurn munary anenes Lungs pieks up uxygen and has earhuh meme Fulmunary Vans Le amurn OOOOOO Left ventricle Aorta Capillaries Posteria anterior vena cava Right atrium Figure 426 I Atrioventrical Valves The Cardiac Cycle I Cardiac cycle rhythmic contraction and relaxation of the heart I Systole contraction or pumping phase Diastole relaxation or lling phase Figure 427 o Atrial and ventricular diastole 04 sec 0 Atrial systole ventricular diastole 01 sec 0 Ventricular systole atrial diastole 03 sec Electrical impulses coordinate the cardiac cycle 0 Pacemaker cells 0 Heart cells that regularly produce spontaneous electrical impulses o Impulses spread throughout heartmuscle cells and stimulates them to contract The Control of Heart Rhythm Sinoatrial SA node primary pacemaker o Gap junctions between cardiac muscle cells allow impulses to travel along atrial cells Atrioventricular AV node second pacemaker cell cluster Figure 428 o Pacemaker generates wave of signals to contract 0 Signals are delayed at AV node 0 Signals pass to heart apex o Signals spread throughout ventricles 0 Physical principles govern blood circulation Concept423 O O O O O 0 Figure 429 Arterie thick walled vessels wsmooth muscle amp connective tissue to withstand high pressure Aterioles branch off of arteries smaller in diameter help control the distribution of blood ow Blood Flow Toward the Heart I Capillaries merge to form venules I Venules merge to form veins Veins I Contain smooth muscle and connective tissue Figure 4210 0 Thinner walled than arteries experience lower pressure 0 Contain oneway valves to prevent back ow o Skeletal muscle contractions compress veins and drive blood movements toward the heart Blood Flow Velocity I The velocity of blood flow caries in the circulatory system I Slowest in capillary beds because of the large totalcross sectional area and resistance I Figure 42 ll 0 Pressure 0 Aorta oscillates because of diastolic pressure and systolic pressure 0 Arteries somewhat oscillated but decreasing pressure 0 Arterioles decreased pressure o Capilarries large dip in pressure 0 Venules decreased 0 Vena cava lowest level of pressure 0 Velocity o Decreases rapidly from arterioles to capillaries then increases slowly to a smaller rate in venules o Slowest velocity in capillaries o Capillary Function I Two mechanisms regulate distribution of blood to capillaries o Contraction of smooth muscle layer in the arterioles contract and dilate o Precapillary sphincters regulate ow 0 Muscles that surround capillaries leading to the beds that can contract and dilate controlling the ow 0 Thermoregulations capillaries contract when cold I Figure 4213 0 Capillary Exchange I Exchange between blood and interstitial uid takes place across walls of capillaries 0 Movement of uid out of the capillaries I Blood pressure and osmotic pressure drives uids out of the capillaries at arteriole end and into capillaries at the venule end I Figure 42 14 0 At arterial end of capillary blood pressure is greater than osmotic pressure and uid ows out of the capillary into the interstitial uid 0 At the venule end blood pressure is less than the osmotic pressure and uid ows from the interstitial uid into the capillary 0 Blood is a connective tissue with cells suspended in plasma Concept 424 0 Two Major Blood Components I Plasma uid portion of blood 0 Makes up 5560 of blood volume 0 90 water 0 Other components 10 hormones nutrients gases salts wastes proteins 0 Figure 4215 I Cellular Components 0 Makes up 45 of blood volume 0 Eythrocytes red blood cells 0 Contains hemoglobin protein responsible for oxygen transport I Picks up oxygen in lungs and releases at tissues 0 Leukocytes white blood cells 0 Lymphocytes T cells amp B cells 0 Monocytes amp neutrophils phagocytes 0 Defense and immunity I Responsible for engul ng harmful bacterias and riding them from the body 0 Platelets o Derived from pieces of megakaryocytes 0 Function in blood clotting I Helps injuries to blood vessels 0 Figure 4215 0 Stem Cells and the Replacement of Cellular Elements I Erythrocytes leukocytes and platelets all develop from a common source I Pluripotenet stem cells in the red bone marrow o Lymphoid stem cells B and T cells 0 Myeloid stem cells erythrocytes platelets monocytes neutrophils eosinophils basophils I Figure 4216 0 Blood Clotting I Damage to the endotheluim of a blood vessel initiates the clotting mechanism I Blood clot is formed from sticky fibrin protein threads platelets and other cells forming a patch over wound site I Figure 42 17 o Endothelium of vessel is damagers exposing connective tissue platelets adhere o Platelets form plug 0 Seal is reinforced by a clot of brin 0 Gas exchange occurs across specialized respiratory surfaces Concept 425 0 Process supplies oxygen for cellular respiration and disposes of carbon dioxide 0 Figure 4119 I Take in 02 reactant of respiration and remove CO2 byproduct of respiration I Form ATP 0 Common features of Animal Respiratory Systems I Respiratory system must be moist so gases can diffuse across cell membranes 0 Gases must dissolved in water rst I Cells lining respiratory surface are thin to optimize gas diffusion o Minimizes distance for gas particles to travel which speeds up the diffusion I Surface area must be large to allow for adequate gas exchange 0 Gills in Aquatic Animals I Thin wall celled structure folding many capillary beds 0 Figure 4220 I Pros and cons of living in water 0 Pros 0 Cells of respiratory surface are kept moist o Cons 0 Oxygen concentrations low in water 0 Warmer and saltier water less 02 I Fish Gills 0 Figure 4221 0 Gas exchange is increased by ventilation and countercurrent exchange 0 Ventilation increasing ow of medium over respiratory surface 0 Countercurrent exchange opposite ow of adjacent uids that maximized transfer rates I High oxygen concentrated water on the end of the oxygen rich capillaries without this there would be no diffusion 0 Water comes in through the mouth runs through the leaflike gills and goes out of the opercelum 0 Pros and Cons of Living in a Dry Environment I Pros 0 02 concentrations much greater in air than water 0 Diffusion is faster in air I Cons 0 Respiratory surface constantly loses water by evaporation o Insect Trachea I Trachea are elaborately branched internal tubes that deliver air to body cells 0 Spread all throughout the body 0 Spiracles tiny holes on sides of body that take in oxygenated air and release carbon dioxide 0 Tracheoles smaller trachea o Facilitated by air sacs I Figure 4222 o Mammalian Respiratory System I Figure 4223 I Path of Air taken in Nose and mouth Pharynx Larynx Trachea Two Bronchi Bronchioles o Alveoli where exchange of oxygen and carbon dioxide takes place 0 Breathing ventilates the lungs Concept 426 o How Amphibians Breathe I Many use gills as larvae and simple saclike lungs as terrestrial adults I Skin used to supplement respiration I Ventilate lungs by positive pressure forces air down the trachea 0 Take in air in mouth and then swallow it down to the lungs o How Mammals Breathe I Mammals ventilate their lungs by negative pressure breathing I Decreasing air pressure in the lungs draws air in I Pressure is inversely related to volume o P UV 0 By increasing the volume the pressure decreases I Figure 4224 0 Inhalation O Muscles of the rib cage contracts causing it to open up and expand o Diaphragm contracts pulling down 0 Both increase the volume decreasing the pressure inside the lungs causing air to be pulled in from the atmosphere 0 Exhalation o Pushing up of diaphragm and rib cage muscles relax o Decreases volume increasing pressure pushing the air out o How a Bird Breathes I Birds have lungs 89 air sacs Function as bellows that keep air owing through the lungs Air passes through the lungs in one direction Always Ozrich air in the lungs Need oxygen for higher altitudes and metabolism to create energy for ying Figures 4225 0 Inhalation in ates posterior air sac o Exhalation air sacs empty lungs ll 0 Respiratory pigments bind and transport gases Concept 427 0 Exchange of gases is governed by concentration gradients I Partial pressures pressure of all the molecules of a certain gas are exerting I 160 mm to 0 Questions 0 If a molecule of CO2 released into the blood in your big tow travels out of your nose it must through all of the following structure except I Pulmonary vein 0 Blood returning to the mammalian heart in a pulmonary vein drains first into the I Left atrium o The primary reason for the decrease blood ow velocity in capillaries is increased resistance I False it is the large totalcross area smaller tubes more area 0 When they are mature and circulating in the blood which of the following cellular elements of blood have no nuclei o Donn I Erythrocytes and platelets o Platelets are fragments of megakaryocytes 0 Red blood cells loose nuclei at maturity concavity helps them obtain oxygen and only last a certain time 0 Which of the following events would cause air to rush out of your lungs I A sudden drastic drop in atmospheric pressure 0 Fluid moves back into the capillaries at the venous end of a capillary bed as a result of I An osmotic pressure that is higher than the blood pressure 0 The trachea of insects I Are highly branched coming into contact with almost every cell for gas exchange Ch 43 Monday Ann 2 2008 AM Cha ter 43 The Immune S stem The group of animals with the most efficient respiratory system is the 7 o ibians O o Mammals o Reptiles Oxygen moves from the alveoli to the bloodstream O o Mainly due to the activity of carbonic anhydrase n the RBCs 0 Through active transport 0 Through osmosis Summary of Innate and Acquired Immunit o Innate Immunity ghts off broad range of assaults on the body Does not target one speci c pathogen I External defenses things that generally keep infectious organisms out 0 Skin 0 Mucous membranes 0 Secretions I Internal defenses fights infection from the inside 0 Phagocytoic cells 0 Antimicrobial proteins 0 Inflammatory response 0 Natural killer cells 0 Acquired immunity targets speci c cells I Humoral response 0 Antibodies I Cellmediated response 0 See gure 431 Concept 431 Innate Immunity provides broad defenses against infection 0 Does not target a speci c pathogen but tries to keep all pathogens at bay 0 External Defenses I Skin is a barrier to microbes Keeps pathogens out of interstitial uids 0 Continuously shed removing microbes that gain a foothold on skin Replaced with younger skin cells Any bacterium or fungus that lands on the skin will be shed off with the skin 0 Many skin secretions contain natural antibiotics 0 Give the skin a pH between 35 0 Also has lysozyme Protects against pathogens that land on the skin Mucous membranes This secretion covers the surface of the epithelium Mucous membrane secretions contain lysozymes Mucus traps microbes entering the nose or mouth Mucous is very viscous therefore organisms can be trapped in it Respiratory tract cilia sweep mucous and microbes away fro the lungs Cilia keeps mucous up toward the pharynx and mouth Any micro organism trapped in the mucus will be kept away from the lungs Internal Defenses Phagocytes Phagocytes types of leukocytes Phagocytosis ingestion of invading microorganisms by certain types of white blood cells 4 types of phagocytic WBCs that will go around the body in the interstitial uid and connective tissues They nd and ingest pathogenic micro organisms o Neutrophills o Macrophages o Eosinophils o Dendritic Cells I Figure 434 Antimicrobial Proteins These proteins function by attacking microbes directly or by impeding reproduction o Complement system causes lysis of invading cells and helps trigger in ammation When a bacterium is detected these proteins are triggered and will bind to the bacterium The proteins will poke holes in the bacterium causing it to lyse Interferons released by virallyinfected cells The cells that are infected will produce these These proteins will bolster the cells immunities to increase immunity against viruses I Helps healthy cells resist infection I Activates macrophages These macrophages kill the viruses that are in the body 0 In ammatory response Part of the immune response to repair tissues and ght off organisms introduced by an injury Chemical signals histamines released by macrophages and mast cells cause capillaries to become more permeable Fluid antimicrobial proteins and clotting elements enter site The uid comes out of the capillaries into the infected area causing swelling This leaking uid has platelets to repair damage Chemokines attract more phagocytic cells In the area of the damage chemokines are released to attract phagocytic cells Phagocytic cells engulf microbes and damaged cells The healthy cells are then able to undergo mitosis to repair damage 0 See gure 436 Natural Killer Cells NK cells 0 Attacks body cells that are virally infected or cancerous When a cell is attacked by a virus the virus uses that cell to create more O In the in amma viruses However before the cell is killed antigens will be placed on the membrane of the cell and the NK cells will recognize these antigens and will kill the virus Cancerous cells cells that have had mutations Will begin to have different recognition proteins on their surface which will be recognized by the NK cells Releases chemicals that initiate apoptosis I Apoptosis cell death Lysis of the cell membrane will occur tory response the absence of which of the following would prevent all the others form happening L EKE eakage of plasma to the affected area Concept 432 in acquired immunity lymphocytes provide speci c defense against infection In vertebrates they also have another line of defense acquired immunity which is carried Increased permeability of capillaries Increased n o ula 39 39 tlon of haoc es in the area nd major kind of defense ivity of lymphocytes Differs from innate because it is very speci c It recognizes antigens and has a memory of them in case of second infection 0 out by lymphocytes 0 Acquired immunit I The body s seco I Involves the act 0 Antigens and Epitopes Antigen any foreign molecule that is speci cally recognized by lymphocytes and elicits a respons e form them Something on the surface of a bacterium virus or a protein that is secreted by bacteria or a molecule introduced to your body Epitope accessible region of an antigen to which an antigen receptor or antibody binds The part of the antigen that the acquired immunity system recognizes Part of the molecule where an antibody can bind See gure 437 Antigen recognition by Lymphocytes o Vertebr O O O Antigen Recept O O O O o O O O O ates have two main types of lymphocytes B lymphocytes B Cells get their name because they complete maturation into the bone marrow T Lymphocytes T Cells their maturation is completed in the Thymus gland therefore T Cells B cells and T cells both have antigen receptors on their plasma membranes These receptors help bind to the epitopes of antigens ors B cell receptors Also known as Membrane antibodies or membrane immunoglobulins because of their shape Have a Y shape two light chains and two heavy chain Consists of two identical heavy chains and two identical light chains linked by several disul de bridges T cell receptors Very strait proteins Imbedded in the plasma membrane Contain a variable region with differing molecular structures at the binding sites Consists of one alpha chain and one beta chain linked by a disul de bridge See Figure 438 0 Concept 433 humoral and cellmediated immunity defend against different types of threats 0 O 0000 0 See Figure 4314 B cells gthumoral immune response make antibodies that attack antigens directly T cells gt cellmediated immune response attack our own cells that are infected Helper T cells release cytokines that activate t cells and b cells Key characteristics of the Acquired Immune System I Has three 0 The immune system recognizes antigens It must recognize and invader o The immune system must launch an attack against the antigens o The immune system must remember speci c invaders to ward off future infection Role of helper T cells in Acquired Immunity I Activated by dendritic cells I The proteins from the surface of a bacterium are now on the surface of the dendritic cell I CD4 enhances binding to antigen presenting cells I This activates the T Cell receptor to release cytokines that stimulate other lymphocytes Cytotoxic T Cells I CD8 a surface protein that enhances binding to target cells I Bing to virallyinfected cells cancer cells and transplanted tissues I Uses porforin which forms pores in cell membrane and granzymes hydrolytic enzymes I Figure 4316 0 Work by recognized antigens that are expressed on the surface of the cell CD8 protein grabs on and allows T receptor to bind to matching antigen T cell then releases porforins poking holes in the cell Granzymes start to ingest cellular components Apoptosis cell death B Cells I Figure 4312 I Cytokines secreted by helper T cells and antigens binding to B cells activates them I B cells attack antigens amp microorganisms that are oating in the plasma I Clonal selection of B cells generates many identical effector cells and longlived memory cells I Figure 4312 0 B cells differ in antigen speci city Figure 4317 I Helper T cell Activated helper T cell I Cytokines I Clone of memory B cells or Clone of plasma cells I Secreted antibody molecules Clonal Selection I Invading antigens bind to antibodies on one B cell I The B ell quotselectedquot by antigen multiplies rapidly I A large clone of genetically identical B cells is produced I B cells differentiate into plasma cells and memory cells Which of the following is not involved in both humoral immunity and cellmediated immunity I Antigens o Involved in both I Plasm 21 cells 0 Only secrete antibodies Helper T cells Activated cytotoxic T cells and B cells I Memory cells 0 Cells of the Immune System Remember Past Victories I Memory B and T cells remain long after the infection I Upon subsequent infenction 0 Memory B cells form active plasma cells that quickly produce many antibodies 0 Memory T cells form active cytotoxic T cells I Figure 4313 0 Exposed to antigen on day 0 o On day 6 there is a noticeable increase in antibody production peaks at day 14 o Infected again after about 30 days and the antibodies have avery rapid production and stay much lon er 0 Quick and effective response to subsequent infection with the same antigen is the logic behind vaccination 0 Antibodies I Antibodies or Immunoglobulins I Yshaped molecules made of light peptide chains and heavy peptide chains I Antigens bind to variable regions of antibodies in a lockandkey fashion 0 Variable regions bind to antigen 0 AntibodyMediated Disposal I Figure 4319 0 Enhancing Phagocytosis 0 Single antibodies oating in blood stream can bing to antigens on the surface of a virus or bacterium 0 Also come in a form where they can bind together and have multiple antibodies in one structure I The group can then bind to the bacterium and immobilize it o Soluble antigens can bind with antibodies to precipitate the antigens o Causing Cell Lysis 0 Activation of complement system and pore formation 0 From the information in the graph when do you nd antibodies being produced Graph Between days 3amp7 and between days 28amp35 antigen exposed at day 0 line increases to peak at day 10 decreases production until day 25 then rapidly increases to day 45 and decreases to a higher concentration than before 0 o Allergies I Figure 0 O Exaggerated selfdirected or diminished immune responses can cause disease Concept 435 Allergies are exaggerated hypersensitive responses to antigens called allergens 4320 Antibodies produced in response to initial exposure to an allergen bind to receptors on mast cells responsible for the in ammation response On subsequent expose to the same allergen molecules attack to a mast cell recognize and bind the allergen Degranulaton of the cell triggered by crossliking of the adjacent molecules releases histamine and other chemicals leading to allergy symptoms Autoimmune Disease Conditions where antibodies and immune systems cells mistakenly attack the body s own CC S Examples Insulindependent diabetes mellitus o Immune system attacks pancreatic cells 0 Com 0 Multiple sclerosis o Attacks cells in the myelin sheaths o Rheymatoid arthritis 0 Attack cartilage in joints Ch 44 Monday April ll 300K 10 4 ANT Ch 44 Osmoregulation and Excretion Osmoregulation o How animals regulate solute concentration and balance the gain and loss of water Excretion o The disposal of nitrogencontaining waste products of metabolism Osmoregulation balanced the uptake and loss of water and solutes Concept 441 o Osmolarity I Solute concentraiton expressed as molarity ie molesL I 2 sucrose solution in bag placed in containers of o 100 water hypoosmotic solution 0 Bag will take in water and expand o 10 sucrose hyperosmotic solution 0 Bag will lose water and shrink o 2 sucrose isoosmotic solution 0 Bag will maintain size water will enter and exit at same rate 0 Osmotic Challenges I Osmoconformers isotonic to their surroundings do not regulate the osmolarity 0 As salinity changes in environment the interstitial uid changes as well I Osmoregulators use energy to control uptake and loss of water I Stenohaline cannot tolerate substantial changes in external osmolarity 0 Stay in an environment that has a stable solute concentration I Euryh aline can tolerate wide uctuations in external osmolarity I An organism can be a stenohaline and a osmoconforrner if they stay in an area was constant salinity 0 Meeting Osmotic Challenges I Marine bony sh 0 Hypoosmotic to sea water 0 Lose water by osmosis gain salts by diffusion I Freshwater sh 0 Hyperosmotic to freshwater o Constantly gain water by osmosis lose salts by diffusion I Figure 443 0 Marine sh have highly concentrated urine while freshwater sh have dilute urine and do so almost constantly to get rid of excess water I Sharks use a different strategy 0 Live in salt water but are hyperosmotic to ocean water 0 They retain high concentrations of urea in body uids 0 Also high concentration of TMAO protects proteins from urea 0 Be sure to soak shark meat in freshwater before eating I Land Animals 0 Skin hair waxy cuticles helps to slow water loss 0 Manage the rest of the water budget by drinking eating moist foods using metabolic water O o Breakdown I Urea o Byproduct of aerobic respiration is H20 Figure 445 o Kangaroo Rat desert animal I Most water from metabolism little bit from ingested food I Most water loss from evaporation then urine then a little from feces ef cient kidners o Humans I Gain most water in liquid some in food and just a little from metabolism Most water loss is from urine then some from evaporation and only a little from feces An Animal39s Nitrogenous Wastes Re ect Its Phylogeny and Habitat Concept 442 Products of Proteins and Nucleic Acids onia Most toxic and most soluble in water Produced by most aquatic animals Diffuses across the body surface or at gills 0 Don39t need urine because they live in water Ammonia converted to urea in live concentrated in the kidners Land animals need to rid ammonia but cannot simply diffuse out of the body because they do no live in water Can store urea at higher levels than toxic ammonia Uric Acid Largely insoluble in water Secreted as a paste with minimum water loss 0 Helps animals conserve water Takes most energy to produce Figure 448 Diverse excretory systems are variations on a tubular theme Concept 443 o Excretory systems regulate solute movement between internal uids and the external environment 0 Excretory Process uids 0 O o Protonephridia o Metanephridia Most excretory systems produce urine by refilling a ltrate derived from bodily Figure 449 Filtration pressure ltering of body uids producing ltrate 0 Not selective so need to filter out the good from bad Reabsorption reclaiming valuable solutes from the ltrate Secretion addition of toxins and other solutes from the body uids to the ltrate Excretion ltrate leaves the system urine FlameBulb System Network of deadend tubules Tubules branch throughout the body Smallest branches are capped by a ame bulb Function in osmoregulation Flatworms Figure 4410 Excretory is mainly to excrete water since they live in water environments and can diffuse ammonia Interstitial uid lters through membrane where cap cell and tubule cell interdigitate interlock Each segment of an earthworm annelid has a pair of metanephridia I Consists of tubules that collect ceolomic uid I Produces dilute urine for excretion I Earthworm Figure 44 ll 0 Problem is taking in excess water and not riding ammonia o Malpighian Tubules I Found in insects and other terrestrial arthropods Removes nitrogenous waste from hemolymph Functions in osmoregulation N containing waste in form of uric acid water conserving adaptation Figure 4412 0 Soil water and nitrogenous wastes come in through the malpighian tubule o Reabsorption of water ions and valuable molecules takes place 0 Feces and urine accumulate in the rectum and are excretes through the anus Nephrons and associated blood vessels are the functional unit of the mammalian kidney Concept 444 o The kidneys are the principle site of water balance and salt regulation in the mammalian excretory system 0 Anatomy of the Human Urinary System I Structures of the urinary system 0 Kidneys o Ureters o Bladder o Urethra I Structure of Kidney 0 Renal cortex 0 Filtration begins 0 Renal medulla o Filtration continues 0 Renal pelvis o Funnel that drains uid into ureter o The Nephron I Bowman39s capsule cuplike structure that contains a capillary glomerulus o Linked to the circulatory system I Tubule proximal tubule loop of Henle distal tubule I Collecting duct collects uid from many nephrons deposits it in the renal pelvis I Figure 4413 campd o The blood vessel leaving the glomerulus has a smaller diameter than the blood vessel entering it This has the effect of I Creating pressure that causes ltration o Leaky Glomerular Capillaries I Glomerular capillary walls are permeable to water and small dissolved molecules I Blood pressure drives ltration from the blood through glomerular walls I F iltrate is deposited into Bowman39s capsule 0 Blood Vessels I Afferent arteriole branch off renal artery to the capillaries I Efferent arteriole form from capillaries that leave the glomerulus I Peritubular capillaries surround proximal and distal tubules I Figure 44 13d 0 From Blood Filtrate to Urine Figure 4414 I Proximal tubule I Descending limb of loop of Henle o Permeable to water but not salts and ions I Thin segment of ascending limb 0 Salt begins to diffuse out I Thick segment of ascending limb o More salt diffuses out I Distal tubule 0 Salt diffuses out water lost be osmosis actively discrete bicarbonate o K and H diffuse in I Collecting duct 0 More salt is excreted 0 Very dilute urine so water leaves by osmosis and is reabsorbed by body 0 Lose urea as well so regulate concentration 0 The mammalian kidney39s ability to conserve water is a key terrestrial adaptation Concept 445 o The kidney can produce urine much more concentration that body uids thus conserving water 0 The TwoSolute Model I NaCl and urea contribute to the osmolarity of the interstitial uid I Countercurrent multiplier system counter current system in which energy is expended in active transport to facilitate exchange of materials and create concentration gradients I Collecting Duct o Permeable to water but not salt Conducts ltrate through the osmolarity gradient More water exists by osmosis Urea diffuses out Urea and NaCl from the osmotic gradient allows kidneys to form hyperosmotic urine I Figure 4415 0 Osmotic gradient more concentrated by inner medulla and less concentrated by cortex 0 Regulation of Kidney Function I Osmolarity of urine is regulated by nervous and hormonal control negative feedback system 0 Controls water and salt reabsorption 0 Figure 4416 0 Stimulus increase in solute concentration losing water due to sweat Hypothalumus releases ADH o ADH increases the permeability of the collecting to water so more water is reabsorbed 0 Also increases thirst I A diuretic is any substance that causes an increase in urine output Which of the following can explain why alocohol acts as a diuretic 0 Alcohol causes the release of endorphins from the brain The endorpth inhibit ADH release 0 I Ch 46 FriJay April 25 31 gt08 944 AM u Ch 46 Animal Reproduction Both asexual and sexual reproduction occur in the animal kingdom Concept 461 o Asexual reproduction type of reproduction involving only one parent that produces genetically identical offspring I Mechanisms Figure 462 o Fission the separation of the parent into two or more individuals of roughly the same size Budding outward growths from the parent form and pinch off to live independently or remain attached and for extensive colonies Fragmentation a single parent breaks into parts the regenerate into whole new individuals Parthenogenesis type of reproduction in which females produce offspring from unfertilized eggs 0 Very common in rotifers and aphids also some vertebrates sh amphibians lizards 0 Figure 463 Females take turn playing the male role in copulation initiating ovulation pseudocopulation I Herm aphroditism 0 Individual has both female and male gonads and functions as both sexes in sexual reproduction 0 Some able to selffertilized ie tapeworms 0 Most must mate with another I Sequential hermaphroditism 0 Individual changes its sex during its lifetime 0 Sexual reproduction type of reproduction in which two parents give rise to offspring that have unique combinations of genes that have unique combinations of genes inherited from the gametes of the two parents 0 Fertilization depends on mechanisms that help sperm meet eggs of the same species Concept 462 0 External Fertilization I Eggs shed by the female are fertilized by sperm in the external environment 0 Internal Fertilization I Sperm are deposited in or near the female reproductive tract fertilization occurs within the tract 0 Increasing Success Rate of Fertilization I Both external and internal fertilization require critical timin o Mediated by environment cues pheromones and or courtship behaviors I Internal fertilization requires important behavioral interactions between male and female animals 0 Increases success rate fewer wasted gametes and helps in choosing mates nonrandom mating 0 Ensuring the Survival of Offspring I External fertilization o More gametes produced but less parental investment 0 Large number of fertilized eggs odds are enough will survive to carry on the species I Internal Fertilization or other means of protecting eggs 0 Fewer gametes produced but more parental investment 0 Tough eggshells development of embryo within the reproductive tract parental car of eggs and offspring 0 Higher portion of offspring will survive because of parental protection 0 Reproductive organs produce and transport gametes focus on humans Concept 463 0 Reproductive Anatomy of the Human Female Figure 469 o Oogenesis Compared to spermatogenesis Cytokinesis is unequal almost all the cytoplasm going to one daughter cell Ova are not continuously made Oogenesis has long quotrestingquot periods Figure 46 ll 0 Oogonium cells in the ovary Form primary oocytes which begin the process of meiosis Only one gamete forms the egg the other forms a polar body Ovum goes into fallopian tubes If it is fertilized it will complete meiosis 2 join with a sperm and form embr o o The Human Female Reproductive Cycle Integrated cycle involving two organs the uterus and ovaries Five hormones participate in the regulation of the cycle 0 GnRH Gonadotropin Regulating Hormone o FSH Follicle Stimulating Hormone o LH Luteinizing Hormone O Estrogen o Progesterone Ovarian Cycle 0 Divided into the Follicular phase and Luteal phase 0 GnRH secretion affects LH and FSH secretion by pituitary o LH and FSH affect follicle maturation 0 Figure 4613 Uterine Menstrual Cycle 0 Divided into the menstrual ow phase proliferative phase and the secretory phase 0 Estrogen and progesterone from the ovaries affect the unterus 0 Reproductive Anatomy of the Human Male Figure 4610 0 Testis are kept in the scrotum hanging away from the body 0 Sperm develop best at a temperature lower than body temperature 0 Scrotom can shrivel and pull testes up into the body in the cold to warm the testis o Sperm is stored after production 0 Vas deferens o Urethra Semen sperm secretions Seminal vesicles mucus fructose coagulating enzyme ascorbic acid prostaglandins Prostate gland anticoagulant enzymes and citrate Bulbourethral gland uid that neutralized any acidic urine in urethra o Spermatogenesis Figure 46 ll Spermatagonia undergo meiosis giving rise to sperm 0 Meiosis l to become primary spermatocyte o Completes meosis l to get secondary spermatocyte O O I Figure 0 Questions Which of the following characterized parthenogenesis An egg develops without being fertilized O O O Meiosis 2 forms spermatids Differentiation to sperm cells in the seminigerous tubule of the testis Sperm Structure Hormonal Control of the Male Reproductive System 4614 Stimuli from other areas in the brain reach the hypothalamus GnRH is produced and brought to the anterior pituatary Anterior pituitary produce FSH and LH Leydig cells making testosterone LH induced and steroli cells FSH induced causing spermatogenesis in the testes GnRH stimulates the release of LH and FSH LH stimulates the Leydig cells to produce testosterone FSH stimulaes that Sertoli cells to begin spermatogenesis helped by testosterone Human Sexual Response Two types of physiological reactions Vasocongestion lling of the tissues with blood Myotonia increased muscle tension skeletal and smooth muscles Nonerect to erect state of penis Blood lls tissue in penis Veins are squeezed shut and arterioles are opened Urethra squeezed shut The sexual response cycle can be divided into four phases Excitement o Myotonia o Vasocongestion erection o Vaginal lubricatoin Plateau o Tenting of the vagina 0 Inner third of vagina gets larger and uterus shifts up I Provides a pocket for the sperm Orgasm o Rhythmic involuntary contraction 0 Release of semen from the penis Resolution 0 Many physiological responses of excitement reverse myotonia and vasocongestion o Refractory Period period in male where they are unable to get excited again for a certain amount of time Seen in rotifers before egg undergoes meiosis it begins developing into an If a hermaphrodite self fertilized will the offspring be identical to the parent No random assortment and crossing over during meiosis will ensure a unique combination of genes upon fertilization Which of the following male and female structures are least alike in function Seminigerous tubules vagina Tubules store sperm vagina is the birth canal Sertoli cells follicle cells aide in production of gametes Spermatogoniaoogonia cells that give rise to sperm and egg Testes and ovaries reproductive organs 0 ma Ch 47 Monday April 2X 20W 103904 le Ch 47 Animal Development 0 Development determined by the zygote s genome and differences between embryonic cells 0 Celldifferentiation the specialization of cells in structure and function 0 Morphogenesis process by which animal takes shape After fertilization embryonic development proceeds through cleavage gastrulation and organogenesis Concept 471 o Fertilization I Brings the haploid nuclei of sperm and egg together forming a diploid zygote I The sperm s contact with the eggs surface initiates metabolic reactions in the egg that trigger the onset of embryonic development division and differentiation 0 The Ascromal Reaction I Figure 473 I Egg cell surrounded by jelly coat and Vitelline layer that has spermbinding receptors When the sperm comes in contact acrosomes break down the jelly coating and activate the sperm micro llaments that bind to the spermbinding receptors I Causes opening of ion channels in the egg cell that depolarize the egg cell make39s sure other sperm cells are unable to come into the e I When recognition happens the sperm cell begins to insert the haploid nucleus 0 Gamete contact andor fusion depolarizes the egg cell membrane and sets up a fast block to polyspermy I All the cells of our bodies have a membrane potential I When the cell is depolarized the charge inside the cell changes 0 The Cortical Reaction I Induces a ride in Ca2 that stimulates cortical granules to release their contents outside the egg 0 Cleaves off receptor proteins and expads fertilization envelope The changes cause formation of a fertilization envelope that functions as a slow block to polyspermy Figure 474 Sperm cell makes contact 0 Point of sperm entry causes release of calcium in that area 0 Spreading wave of calcium ions 0 Calcium starts different metabolic processes in the egg cell that causes the division and differentiation 0 Activation of the Egg I The sharp rise in calcium in the eggs cytosol increases the rates of cellular respiration and protein synthesis by the egg cell Events occuring upon activation in a sea urchin egg Figure 475 Binding of sperm to egg Acrosomal reaction plasma membrane depolarization Increased intracellular calcium level Cortical reaction begins Formation of fertilization envelope complete Increased intracellular pH Increased protein synthesis Fusion of egg and sperm nuclei complete 0 Fertilization in Mammals I Figure 476 O O O O O O I In mammalian fertilization the cortical reaction modi es the zonapellucida as a slow block to polysperrny Cleavage I Fertilization is followed by cleavage a period of rapid cell division without growth I Cleavage partitions the cytoplasm of one large cell into many smaller cells called bastomeres I Figure 477 Zygote Polarity I The eggs and zygotes of many animals except mammals have definite polarity I Polarity is defined by distribution of yolk with the vegetal pole having the most yolk I The development of body axes in frogs is in uenced by the eggs polarity I Figure 478 Cleavage Patterns I Cleavage planes usually follow a pattern that is relative to the zygote39s animal and vegetal poles I Figure 479 Cleavage and Egg Yolk I Meroblastic cleavage o Incomplete division of the egg occurs in species with yolkrich eggs 0 Retiles and birds I Holoblastic cleavage 0 Complete division of the egg occurs in species whose eggs have little or moderate amounts of yolk 0 Sea urchins and frogs I Figure 4710 Gastrulation I Gastrulation rearranges the cells of a blastula into a threelayered embryo called a gastrula which as a primitive gut I Embryonic germ layers 0 Ectoderm forms the outer layer 0 Endoderm lines the digestive tract 0 Mesoderm partly lls the space between the endoderm and ectoderm Sea Urchin 0 Figure 47 ll 0 Some cells begin to bud off the vegetal pole that will form the mesoderm 0 Forms blastopore and cells continue to invaginate into the blastocoel 0 Finally forms digestive tube endoderm I Fro Figure 4712 More complex Dorsal lip of blastopore cells begin to fold in here Form the archenteron or early digestive system 0 Mesoderm grows around the endoderm and ectoderm surrounds all Chicken 0 Figure 4713 0 Emryo forms completely from the epiblast cells 0 Epiblasts fold in along primitive streak 0 Some bud off forming mesoderm and other the endoderm and ectoderm Organogenesis Figure 4714 I Neural Plate Formation 0 During organogenesis various regions of the germ layers develop into rudimentary organs oooom 0 Early in vertebrate organogenesis the notochord forms from mesoderrn and the neural plate forms from ectoderm I Formation of Neural Tube 0 The nueral plate soon curves inward forming the neural tube 0 Neural crest cells are unique to vertebrates 0 Form peripheral nerves teeth skill bones etc 0 4th germ layer I Somites o Mesoderm lateral to the notochord forms blocks called somites 0 Form segmental structures like vertebrae skeletal muscle 0 Lateral to the somites the mesoderrn splits to form the coelom 0 Figure 4716 I Ectoderm Mesoderm and Endoderm Developments 0 Questions 0 If you injected Ca2 into an unfertilized sea urchin egg what would happen I The egg would undergo the cortical reaction thus preventing fertilization o How many cells make up this egg yolk if the embryo is at the zygote stage I One 0 Which developmental sequence is correct March 21 2012 Spongebob belongs to which phylum Porifera In the life cycle of a typical hydrozoan which of the following would most likely be free swimming Medusa Rotifers fig 3313 Phylum Rotifera Alimentary canal w separate mouth amp anus Pseudocoelomate Reproduce by parthenogenesis there are females and the eggs in the females are able to develop into new individuals without fertilization Phylum Molluscaf1g 3315 have a radula rasplike feeding organ scraps and scoops food items most mollusks have an open circulatory system Class Polyplacophoraf1g 3316 aka Chitons shell has 8 plates foot used for locomotion radula no true head Class Gastropodaf1g 3317 amp 3318 snails and slugs assymmetrical body usually with a coiled shell result of torsion rotation of the Visceral mass foot for locomotion radula Class Bivalviaf1g 3319 amp 3320 clams mussels scallops oysters attened shell with 2 valves head reduced paired gills no radula mostly suspension feeders Class Cephalopodaf1g 3321 squids octopods cuttlefish chambered nautili head surrounded by grasping tentacles usually with suckers shell may be external internal or absent Which of the following combinations of phyla and characteristics is incorrect Rotifera 7 partheno genesis cnideria 7 radial symmetry polyp and medusa body form platyhelminthes 7 atworms gastrovascular cavity p01ifera gastrovascular cavity 2 tissue layers Phylum Annelida annelids are coelomate coelom completely lined by mesoderm Anatomy of an Annelid e g earthworm fig 3324 body is divided into segments each segment has a set ofmuscles contract against coelomic uid hydrostatic skeleton closed circulatory system w 5 pumping vessels hearts alimentary canal w specialized regions metanephridium excretory tubes that remove wastes from blood and coelomic uid cerebral ganglia functions as a rudimentary brain Ventral nerve chord w segmented ganglia Annelid Diversity oligochaete earthworms polychaetes found in green environments ocean etc means many bristles fig 3322 hirudinea leeches 7 mostly parasitic produce anticoagulate in their saliva which can be useful ex Blood thinning med fig 33 m Echdysozoans are the most species rich animal group Phylum Arthropoda 2 out of every 3 known species of animals are arthropods have 4 subphyla General Characteristics of Arthropods Arthropod body is covered by an exoskeleton made of chitin when an arthropod grows it sheds the exoskeleton by a process called ecdysis arthropods have an open circulatory system hemolymph is circulated into spaces surrounding tissues Variety of gas exchange organs gills tracheal tubes book lungs if opened like a book would have layers of membranes like pages Subphylum Cheliceriformes g 333l amp 3332 scorpions spiders ticks mites and horseshoe crabs Arachnid Anatomy g 3333 includes scorpions spiders ticks and mites body has 2 regions cephalothorax abdomen cephalothorax has 6 pairs of appendages pedipalps chelicerae for spiders their fangs For scorpions its their pinchers 4 pairs of walking legs book lungs for respiration March 23 2012 Three ofthe four animals listed below possess some type of coelom Select the exception 1 annelids 2 arthropods 3 molluscs 4 platyhelminths Subphylum Myriapoda millipedes amp centipedes millipedes 7 class Diplopoda g 3333 2 pairs of legs per segment Detritus feeders in leaf litter centipedes 7 class Chilopoda g 3334 1 pair of legs per segment ca1nivores Subphylum Hexapoda g 3338 insects and their relatives more species rich than all other animals combined Insect Anatomy g 3335 insects are characterized by haVing 3 pairs of walking legs on the thorax l or 2 pairs of wings 3 body regions have open circulatory system where heart pumps hemolymph around organs cerebral ganglion and sense organs antennae and eyes are concentrated in head gas exchange occurs through tracheal tubes air enters and exits through spiracles Subphylum Crustacea g 3330 shrimp lobsters crabs craw sh biramous appendages gills for gas exchange Echinoderms and chordates are deuterostomes f1g 329 Echinoderms may not look like chordates which includes vertebrates but they share a common developmental plan Deuterostomes radial cleavage coelom develops from archenteron mouth forms opposite of blastospore Phylum Echinodermata f1g 3340 Echinoderm spiny skin slow moving or sessile marine animals pentaradial symmetry unique watervascular system water ows in and out of the watervascular system through the madreporite watervascular system consists of ring canal and radial canals Branching from radial canals are the tube feet Tube feet are used for locomotion capturing and attracting substrates Echinoderm Diversity g 334044 Summary of Animal Phyla table 337 Chordate Phyloeny fig 342 body plan gets more complex With time Which of the following statements is not true 1 All chordates have notochords All chordates have pharyngeal pouches All chordates have a postanal tail All chordates have vel tebrae 2 3 4 Chordates have a notochord and a dorsal hollow nerve chord Chordates are deuterostome bilaterian animals 2 chordate subphyla are invertebrates Urochordata Cephalochordata 3rd subphylum Craniata includes the vertebrates Derived Characteristics of Chordates f1g 343 All chordates share 4 derived charateristics notochor dorsal hollow nerve cord pharyngeal slits or clefts Muscular postanal tail Although some species possess some of these traits only during embryonic development Tunicates fig 345bampc Subphylum Urochordata Sessile marine suspension feeders draws water in through incurrent siphon ltering food particles Tunicates posses the chordate characteristics during their larval stage fig 345a Lancelets fig 344 Subphylum Cephalochordata marine suspension feeders retain chordate features throughout lifespan Which of the following is a diagnostic feature of tunicates that forms the basis for its classification as a chordate l Metamorphosis from a motile larva to a sessile adult 2 A heart that allows circulation of blood 3 A notochord located along the dorsal part of the larva 4 Sexual reproduction during the larval stage m Craniates are chordates that have a head Subphylum Craniata The origin of the head in chordates allowed some to become active predators Shared characteristics in craniates cranium brain eyes amp other sensory organs Hagflshes fig 349 Class MyXini The least derived extant of species of Craniate jawless marine craniates cartilagenous skull amp aXial rod derived from notochord no vertebrae scavengers prey upon dead fish defenses slime glands that release slime when bothered March 26 2012 m Vertebrates are craniates that have a backbone They have vertebrae enclosing a spinal chord an elaborate skull fm rays in aquatic forms Lampreys g 3410 Class Petromyzontida oldest living lineage of vertebrates vertebrae are cartilaginous segments surrounding the notochord and arching partly over the nerve chord jawless found in marine amp freshwater parasitic 7 latch onto the sides of sh with keratin teeth Origins of Bone amp Teeth g 3411 amp 3412 Mineralization appears to have originated with vertebrate mouthparts Conodonts were 1St with mineralized mouth amp pharyngeal parts Ostracoderms had mineralized plates on their skin Endoskeleton became mineralized later The most primitive but still existing craniates are members of the class 1 Myxiniquot 2 Petromyzontida 3 Chondrichthytes 4 Osteichthyes v 3 D Gnathostomes are vertebrates that have jaws The most successful group of vertebrates alive today Derived Characteristics of Gnathostomes g 3413 Jaws Evolved from skeletal supports of the pharyngeal slits Enhanced sensory system including lateral line system mineralized endoskeleton paired appendages Chondrichthyans Sharks Rays amp Their Relatives g 3415 Class Chondrichthyes Includes sharks rays and rat shes sharks are streamlined amp swift swimmers rays are dorsoventrally attened RayFinned Fishes amp LobeFins Most vertebrates belong to a clade called Osteichthyes including ourselves have bony endoskeleton aquatic osteichthyans ve1tebrates we call shes RayFinned Fishes g 3417 Class Actinopterygii familiar aquatic osteichthyans ns supported by long exible rays Lobe Fins g 3418 amp 3419 Sarcopterygii Rodshaped bones surrounded by muscle in pectoral and pelvic ns Class Actinistia 7 coelacanths Class Dipnoi 7 lung shes l39 11 z 39 New body features do not usually appear from scratch but result from the modi cationof existing features to serve other functions What feature became modi ed to form jaws 1 the cranium 2 the primitive forelimbs 3 gill archesquot 4 the notochord Sharks skates and rays belong to the class 7 1 Reptilia 2 Chondrichthyes 3 Sarcopterygii 4 Actinopterygii m Tetrapods are gnathostomes that have limbs Derived Characteristics of Tetrapods F our limbs and feet with digits In some forelimbs are modi ed for grasping bipeds or ight e g birds Ears for detecting airborne sounds no lateral line system Origin of Tetrapods g 3421 based on fossil discoveries Amphibians g 3422 Class Amphibia Order Urodela salamanders Order Anura frogs amp toads Order Apoda caecilians Moist skin that complements lungs in gas exchange Amphibian means two lives g 3423 live between aquatic and terrestrial habitats tied to water for reproduction eggs desiccate out of water larvae are often aquatic If an amphibian could be a plant which plant would it be 1 Monocot 2 Mossquot needs water for reproduction 3 Cycad 4 Gnetophyte m Amniotes are tetrapods that have terrestrially adapted eggs g 3425 Derived Characteristics of Amniotes Fig 3426 Amniotes get their name from the amniotic egg egg with specialized membranes that protect the embryo relatively permeable skin ability to use rib cage to ventilate the lungs Amnion protects embryo in a uid lled cavity Allantois disposal sac for certain metabolic wastes Also functions w chorion as a respiratory organ Chorion exchanges gases between embryo and the air Yolk sac provides nutrients for the developing embryo March 28 2012 Why is the amniotic egg considered an important evolutionary breakthrough It 7 1 has a shell that increases gas exchange 2 allows incubation of eggs in a terrestrial environment 3 prolongs embryonic development 4 provides insulation to conserve heat energy Reptiles The reptile clade includes the tuatara lizards snakes turtles crocodilians birds and the extinct dinosaurs have scales that create a waterproof barrier lay shelled eggs on land mostly ectothermic absorb external heat as the main source of body heat exception is the birds which are endothermic Turtles g 3429d the most distinctive group of reptiles alive today all turtles have a boxlike shell made of upper and lower shields that are fused to the vertebrae clavicles amp ribs Lepidosaurs g 3429a b amp c two lineages of lepidosaurs tuataras squamates Tuataras 7 lizardlike reptiles Squamates include the lizards and snakes Archosaurs g 3429e includes the dinosaurs extinct and the living crocodilians and birds Birds birds are Saurischian Archosaurs but their anatomy has undergone modi cation in their adaptation for ight no urinary bladder females have 1 ovary males amp females have small gonads light skull amp no teeth Adaptation for Flight g 3430 most obvious adaptation for ight are the wings and feathers m Mammals are amniotes that have hair and produce milk g 344l Derived Characteristics of Mammals Mammary glands that produce milk hair and insulating layer of fat beneath skin diaphragm to help ventilate the lungs generally larger brain that other vertebrates of equivalent size eXtended care period for the young differentiation of teeth Early Evolution of Mammals g 3437 Mammals evolved from synapsid reptiles modi cation of the jaw bones is distinctive in mammals Clicker Which is not characteristic of all mammals l a fourchambered heart 2 have hair at some period of their life 3 have glands to produce milk to nourish their offspring 4 give bilth to live young Viviparous Monotremes g 3438 includes the platypus and spiny anteater lay leathery eggs nourish young with milk but no nipples Marsupials g 3439 3440 includes opossums kangaroos koalas young are born very early in development and crawl to marsupium pouch development is completed within the pouch Eutherians Placental Mammals Eutherians have a longer period of pregnancy Eutherians complete embryonic development within a uterus joined the mother by a placenta The Major Eutherian Orders g 344l Clicker Below are taxonomic categories matched with a common name of an animal Which of these is incorrectly matched Dipnoi 7 lung sh actinopterygii 7 rayfmned shes apoda caecilians archosauria lizards and snakes 99 CHAPTER 40 Basic Principals of Animal Form and Function Concept 401 Animal form and function are correlated at all levels of organization physical laws especially physics of exchanging materials with environment limits range of animal forms Clicker Is this possible here on Earth gigantic singlecelled amoeba the size of spaceships Yes 2 No surface area to volume ratio surface area isn t large enough to exchange materials to keep up with the volume demand Exchange in Simple Organisms g singlecelled organisms exchange material by diffusion entire plasma membrane is exposed to medium multicellular organisms with a sac body plan body wall is only 2 celllayers thick exchange materials by diffusion Exchange in Complex Animals g large complex animals have highly folded or branched internal surfaces specialized for exchanging materials this increases surface area March 30 2012 The organization of the animal body involves a hierarchy of structures The correct order og this hierarchy from least to most complex is cells organs tissues organ systems tissues cells organ systems organs organs tissues cells organ systems cells tissues organs organ systems pwwe Epithelial Tissue g 405 covers the outside of the body and lines the organs and cavities within the body cells are closelyjoined Connective Tissue g 405 functions mainly to bind and support other tissues composed of sparsely packed cells scattered throughout an extracellular matrix maj or types loose connective tissue adipose tissue brous connective tissue cartilage bone blood Muscle Tissue g 405 composed of long cells called muscle bers capable of contracting in response to nerve signals 3 types skeletal cardiac smooth Nervous Tissue g 405 sense stimuli and transmit signals throughout the animal nerve cell responsible for receiving and transmitting is the neuron Organ Systems table 401 organ systems carry out the major body functions of most animals Control amp Coordination g 406 animals need to coordinate activities among organs two systems responsible endocrine slow response but long lasting nervous quick response but short lived Feedback control maintains the internal environment in many animals interstitual uid that lls space between cells intemal environment exchange occurs with cells here homeostasis maintaining in internal variables within an acceptable range Regulating amp Confronting g 407 regulator uses internal control mechanisms to moderate internal change in the face of external uctuation conformer allows internal conditions to vary with certain external changes The organism in which these measurements were made is an osmoi and a thermali conformer regulator regulator c0nf0139mer conformer conformer regulator regulator eP Equot Mechanisms of Homeostasis fig 408 Homeostatic control systems have three functional components receptor control center effector Negative Feedback fig 408 amp 4016 response to change is to counteract the change resulting in a return to the original condition Negative because it negates the initial change Positive Feedback intensif1es the original change when the need exists drives events to a conclusion tends to be self limiting Which of the following is the correct sequence involved in the regulation of homeostasis stimulusreceptorcontrol centerresponseeffector stimulusresponsecontrol centerreceptoreffector stimulus receptor control center effector response stimuluscontrol centerreceptoreffectorresponse bP Nf i i v Homeostatic processes for thermoregulation involve form function and behavior Thermoregulation process by which animals maintain an internal temperature w in a tolerable range Ectotherms use environmental energy and behavioral adaptations to regulate body temperature Endotherms use metabolic heat to regulate body temperature Ectotherms and Endotherms fig 4070 Ectotherms eg most invertebrates shes amphibians and nonbird reptiles Endotherms eg birds and mammals April 2 2012 Hypertension produces damage to the lining of the arterioles of the kidneys which results in the release of molecules that will further raise blood pressure This is an example of an 7 negative feedback loop positive feedback loopquot controlling mechanism uncontrolled mechanism Awwe Modes of Heat Exchange fig 4011 radiation evaporation convection conduction Balancing Heat Loss amp Gain Insulation reduces the ow of heat between an animal and its environment includes feathers fur blubber skin Circulatory adaptations fig 4012 vasodilation blood ow to the skin increases facilitating heat loss vasoconstriction blood ow to the skin decreases lowering heat loss counter current exchange Cooling by Evaporative Heat Loss Evaporation from a surface causes heat loss sweating panting bathing Other Behavioral Responses fig 4013 basking in the sun and moving into the shade maintaining a certain posture For which of the following animals would the percent of its energy budget spent for homeostatic control be the largest a marine jelly sh a snake in a temperate forest a desert insect an arctic birdquot 99 Energy requirements are related to animal size activity and environment Biogenetics the ow of energy through an animal Energy Sources amp Allocation g 4017 Animals harvest chemical energy from food Energy containing molecules are broken down to make ATP Once energetic needs are met remaining molecules are used in biosynthesis Quantifying Energy Use g 4018 Metabolic rate the amount of energy an animal uses in a unit of time can be measured by the amount of oxygen consumed or carbon dioxide produced by an organism Size amp Metabolic Rate g 4019 amp 4020 A mouse and a lizard with the same body mass were placed in experimental chambers and their metabolic rates were measured over a range of temperatures From the data shown on the graph which were collected from the mouse and which from the lizard 1 Alizard B mouse 2 A mouse B lizard 3 can t tell endotherms will always have higher metabolic rates than ectotherms Minimum Metabolic Rate amp Thermoregulation Basal Metabolic Rate BMR metabolic rate of an endotherm at rest Standard Metabolic Rate SMR metabolic rate of an ectotherm at rest di erent because endotherms maintain such a high metabolic rate all the time An animal s diet must supply chemical energy organic molecules and essential nutrients chemical energy organic molecules mostly supplied by carbohydrates proteins amp lipids other nutrients include vitamins and minerals Essential Nutrients g 412 Essential amino acids are ones that animals can t synthesize Animals require 20 amino acids complete proteins incomplete proteins Essential fatty acids are required in the diet Usually unsaturated fatty acids humans need linoleic acid April 4I 2012 Which choice offers best time to measure basal metabolic rate x an adult at rest prior to its first meal of the day bc cannot have any digestion Vitamins table 411 Vitamins are organic molecules Serve as antioxidants amp coenzymes Minerals in small amounts Inorganic elements or compounds in the diet Ex Calciumphosphorus ironhemoglobin CQ Which of the following vitamins can be stored in the bodies of animals x vitamin E bc fat soluble in adipose tissue C and B are water soluble so are washed out Concept 412 the main stages of food processing are ingestion Digestion absorption and elimination 4 stages of food processing 1 ingestion food brought in through the mouth 2 digestion mechanical is physical breakdown of food chemical is digestive chemicals and enzymes breakdown food 3 absorption small subunits transported out of digestive system 4 elimination indigestive material expelled from body intracellular digestion sponges are sedentary filter feeders with no specialized digestive system digestion takes place in collar cells lining waterfilled spongocoel 1water carrying food particles enter pores 2food particles are filtered by collar cells 3food enters by endocytosis 4food digested by lysosomes CQ Which of the following possesses a gastrovascular cavity platyhelminthes Hydra have a gastrovascular cavity Opening acts as both a mouth and anus Gland cells release enzymes and break down food Nutritive cells absorb nutrients and food particles Indigestive material expelled out of mouth Digestion in a tube is more efficient Alimentary canal complete digestive tract that has digestive tube with a mouth and anus Digestive tube can be organized into specialized regions Allows animals to eat more frequently Concept 413 organs specialized for sequential stages offood processing form the mammalian digestive system Major organs mouth pharynx esophagus stomach small intestine large intestine rectum anus accessory organs salivary glands secrete saliva amylase liver secretes bile gallbladder stores and concentrates bile pancreas secretes digestive enzymes spaswszvse the oral cavity pharynx esophagus mechanical and chemical breakdown of food begin in the mouth chewing is mechanical by teeth salivary glands produce saliva to start chemical breakdown of food functions of saliva amylase breakdown starches into small polysachharides and disaccharides bacteria killing enzymes and antibodies lubricate food and helps with swallowing carries food molecules to taste buds on tongue for food quality identi cation from mouth to stomach I tongue pushes food into pharynx intiating swallow re ex 2 larynx moves up and tips epiglottis over the glottis 3 esophageal spinter releases allowing bous to enter the esophagus 4 waves of muscular contraction move bolus down esophagus to stomach stomach stomach has 3 major functions 1 food storage and gradual release into small intestine 2 mechanical breakdown of food by churning contractions smooth muscle 3 chemical breakdown by stomach gland secretions acid stomach secretions hcl makes stomach uid very acidic and is secreted by parietal cells pepsinogen is secreted by chief cells and is inactive enzyme converted into active pepsin when exposed to hcl mucus protects the stomach wall from acid and is secreted by mucus cells concept 414 evolutionary adaptations of vertebrates digestive system are often associated with diet carnivore canines are large with incisors and small premolars and molars herbivores canines are small and large premolars and molars for chewing cellulose omnivores compromise between herbcam digestive specializations intestinal length is correlated with diet bc cell walls are difficult to digest herbivore intestines cecum are large to allow more time for nutrient absorption carnivore intestines cecum are short bc proteins are easy to digest ruminant digestion ruminant animals animals that are able to break down cellulose and extract nutrients from tough plant matter practice rumination regurgitate and rechew food cud digestive systems house microorganisms which break down cellulose CQ Purpose of bicarbonate ions secreted from pancreas into small intestine is too X neutralize acidic chime from stomach April 16 2012 Which of the following components of a hamburger would leave the stomach undigested Protein 2 starch 3 disaccharides 4 lipids 5 6 b0th3 amp 4 l 2 amp 3 The Small Intestine g 4114 The small intestine is anarrow tube about 6 m long Most digestion occurs in the small intestine Intestinal Secretions Cells lining wall of the small intestine brush border secrete enzymes that complete digestive process disaccaridases breakdown disaccharides into monosaccharides dipeptidases carboxypeptidases aminopeptidases complete breakdown of peptides into amino acids nucleotidases nucleosidases phospatases breakdown of nucleic acids into sugars nitrogenous bases and phosphates Pancreatic Enzymes fig 4114 pancreas secretes pancreatic juice which is released into the small intestine pancreatic juice components water sodium bicarbonate amylases trypsin chymotrypsin carboxypeptidases nucleases lipases 1 1121quot 39 The majority of chemical digestion occurs in the 1 mouth 2 stomach 3 small intestinequot 4 large intestine Why does salivary amylase not hydrolyze starch in the small intestine 1 Starch is completely hydrolyzed into glucose in the mouth 2 The low pH in the stomach denatures salivary amylase and pepsin begins hydrolyzing it salivary amylase is produced by salivary glands and never leaves the mouth pancreatic amylase is a more effective enzyme in the pH of the small intestine As Fat Digestion liver produces bile bile stored in gallbladder then secreted into small intestine bile emulsifies fat breaks them into smaller droplets gives enzymes greater surface area to work on Fig 4113 Absorption ofNutrients fig 4115 The small intestine is well adapted for absorption of nutrients Su1face area is increased by numerous folds with ngerlike projections villi and microvilli Into the Blood amino acids sugars amp components of nucleic acids pass through the epithelium of small intestine amp enter blood stream Fat Absorption fig 4124 lipases digest fat into monoglycerides amp fatty acids enter intestinal epithelium then recombined into fats amp form chylomicrons leave epithelial cells amp enter lacteals part of lymphatic system The Large Intestine aka the colon about 15 m long absorbs leftover water vitamins and salts contains bacteria that consume unabsorbed nutrients and synthesize vitamins feces transported by peristaltic contractions to the rectum rectum expands and stimulates defacation Concept 414 Evolutionary adaptations of vertebrate digestive systems are often associated with diet fig 4118 Digestive Specializations fig 4119 Intestinal length is correlated with diet because cell walls are difficult to digest herbivore intestines are long to allow more time for nutrient absorption ca1nivore intestines are relatively short because proteins are easy to digest Ruminant Digestion fig 4120 Ruminant animals herbivores that are able to break down cellulose and extract nutrients from tough plant matter practice rumination regurgitate and rechew food cud digestive systems house microorganisms which break down cellulose The purpose of bicarbonate ions secreted from the pancreas into the small intestine is to 71 neutralize the acidic chime coming from the stomach 2 emulsify fat molecules so lipases can digest them easier 3 digest polysaccharides and disaccharides into monosaccharides 4 convert trypsino gen into trypsin Biology Notes 1202 Ch 22 1262012 45400 AM Chapter 22 Evolution two main ideas o Change over time of the genetic composition of a population o Decent of modern organisms with modification from preexisting organisms Evolutionary adaptation o Accumulation of inherited characteristics that enhance organisms ability to survive in specific environments PreDarwinian Theory of Evolution Lamarck o Use and disuse o Bodies of living organisms are modified through the use or disuse of parts o Inheritance of acquired characteristics 0 These modifications are inherited by offspring o These ideas turned out to be wrong Evolution by Natural Selection Darwin and Wallace developed the theory independently o Darwin voyage of the Beagle o Wallace naturalist in Indonesia Natural Selection o The unequal survival and reproduction of organisms due to environmental forces resulting in the preservation of favorable adaptations o Process selects from what is available in the gene pool o New characteristics are not created on demand o Page 458 Mechanism Behind Natural Selection Think about the 100m dash track and field competition How can we change this race to reflect the process of natural selection Artificial Selection o Selective breeding of organisms to encourage the occurrence of desirable traits o Analogous to natural selection c Figure 229 Concept 223 Evolution is supported by an overwhelming amount of scientific evidence Figure 2213 Homologous and Analogous Structures o Homologous 0 Structures or other attributes in different species that resemble each other because of common ancestry o Vertebrate Embryos All vertebrates share similar development genes Differences arise by some genes being switched on or off at varying times during development 0 Biochemistry and Molecular Biology DNA is a universal genetic material All life forms use approximately the same 20 amino acids to make proteins All use ATP as the primary form of cellular energy All use RNA and ribosomes to make protein o Analogous 0 Structures that are similar in function but not in structure and developmental and evolutionary origin Trees vs Scala Nature o ScalaNaturae 0 Ladder of nature page 453 o Evolution not about climbing ladder of nature from lower to higher o Evolution is a bush with lineages branching from one another Convergent Evolution o Similarity bn two organisms structures or molecules due to independent evolution along similar lines rather than descent from a common ancestor Figure 2218 Fossil Record c Show change in organisms through time o Change in types of organisms 0 Past organisms differ from presentday organisms 0 Many species have become extinct o Not only provides evidence of smallscale changes but of origin of major groups Figure 2220 c Eg the cetaceans Figure 2219 What is least likely to represent homology o The legs of a bird and those of an insect Chapter 23 The Evolution of Populations The smallest unit of evolution o One common misconception about evolution is that individual organisms evolve during their lifetime o Evolutionary processes eg natural selection acts on individuals but populations evolve Concept 231 Genetic variation makes evolution possible Mutation o Mutations changes in nucleotide sequence of DNA 0 Source of ne alleles and genes o Point mutation change in one nucleotide base in a gene o Chromosomal mutations delete disrupt or rearrange many loci on a chromosome o Gene duplications duplication of whole segments of a chromosome o Mutation rate averages 1 in every 100000 genes per generation Sexual Recombination o In sexual reproducing organisms sexual recombination produces most of the variability in each generation Variation within a Population o Discrete characters classified on an eitheror basis 0 Eg flower color in pea plants o Quantitative characters vary along a continuum within a population 0 Eg height weight Concept 232 The HardyWeinberg equation can be used to test whether a population is evolving Populations o A group of individuals of the same species living in a certain defined area Figure 236 HardyWeinberg Equilibrium o Describes a population that is not evolving ie allele frequencies don t change o Five assumptions behind HW equilibrium No mutations Large population size No gene flow No natural selection 0 Random mating Allele and Genotype Frequencies o Allele frequencies 0 Pfrequency of allele 1 qfrequency of allele 2 o P Q l o Genotype frequencies 0 P2 frequency of homozygous dominant 0 Q2 frequency of homozygous recessive o 2pq frequency of heterozygotes 0 p2 2pq q2 1 HW equation HW Equilibrium c Figure 237 Population genetics and human health o HW equation can be used to estimate of the human population carrying the allele for an inherited disease o PKU is a recessive genetic disorder 0 Frequency of homozygotes w this disorder is q2 00001 0 What is the frequency of the dominant and recessive alleles p q The frequency of carriers heterozygous people who do not have PKU is 392 Answer 00198 Why q2 00001 Q 01 P 99 P2 2pq q2 1 gt 299010198 O O O 0 If the frequency of the recessive allele is 30 the frequency of the heterozygous carriers would be o 9 27 42 D 0 p70 2pq2307042 or 42 Concept 233 Natural selection genetic drift and gene flow can alter allele frequencies in a population Genetic Drift o Statistically the smaller a sample the greater the chance of deviation form a predicted result o With small population sizes allele frequencies can fluctuate unpredictany from one generation to the next o Tends to reduce genetic variation c Figure 239 o Founder effect 0 The frequency of red allele is low on original population on island 0 Several of the travelers happen to carry the red allele 0 Frequency of red allele much higher in 0 GET THIS FROM HANNA Bottleneck Effect and Reduction of Genetic Variation c Figure 2310 Gene flow o Genetic additions to or subtractions from a population resulting from the movement of fertile individuals or gametes o Migration among populations o Tends to reduce variation among populations over time Concept 234 Natural selection is the only mechanism that consistently causes adaptive evolution Natural selection o Differential success in the reproduction of different phenotypes resulting from their interactions with the environment Evolutionary fitness Fitness the contribution an individual makes to the gene pool of the next generation relative to the contributions of other individuals Tom Dick Harry Size 6 3 5 10 5 5 200lbs 185bs 124bs CHILDREN 2 3 5 COMMENTS Ladies Man Athlete Nerd Harry wins Directional Disruptive and Stabilizing Selection Figure 2313 1262012 45400 AM 1262012 45400 AM Bio 1202 exam 3 chapters 3538 PART 1 Brandon Cohen s pretest questions which conduct water and minerals with xylem Tracheids and vessel elements cells that transport carbs SIEVE TUBE ELEMENTS Nitrogen fixation is the process of converting N2 to NH3 ammonia know clay sand and silt seed leavesCOTYLEDON horizon a b and c know those too What is not true about the hypocotyl hookanswer FIRST STRUCTURE TO EMERGE FROM DICOT SEED And the true facts are 1 it straightened when exposed to light it pulls cotyledons up thru soil and it is the region below the cotyledon The pericycle is important to plants because An epiphyte is a plant that You take out the roots on a plant ant notice root nodules on the roots What does this mean A diagram of a branch with one leaf on itwhat type of leafis it doubly compound simple or compound Which tissue gives rise to all the others Pericycle meristem or something else I think it is meristematic CASPARIAN STRIP is waterproof badn that prevents water from entering vascular cylinder from APOPLASTIC ROUTE Order the correct ow of sugar intake 1 photosynthesis makes the sugar 2 sugar is moved into sieve tubes 3 water is taken up via osmosis 4 water moves from cell to cell 5 sugar reaches the sink Order in which male gametophyte is formed in angiosperms Microsporocyte meiosis microspore mitosis male gametophyte In ux of K ions causes GUARD CELLS TO OPENCLOSE Question 1 wasretain ability to divide yes no no high of mesophyll yes no no Hi number found in young stems yes yes no Double fertilizationI put unique to angiosperms It was one of those questions with multiple boxes and you select the correct answer for the correct statement and there were 4 statements Embryo sac Pollen grain Stamen Carpel Order the following from outside to inside 1 cortex 2 phloem 3 xylem 4 pith Which pair is equivalent I put ovule and egg Correct order to get to the female gametophyte 1 megaspore 2 meiosis 3 female megasporocyte 4 mitosis 5 female gametophyte a plant has primary growth but no secondary growth What can be observed from this I put no lateral layers will be added PART II noteswap questions dermal tissueon outside cell is alive with no nucleus Sieve tube what are part of the lateral meristem Vascular and cork cambium Sugars transported thru PHLOEM Ifyou increase the of solute you DECREASE water potential Not sure if this is correct Question on my pretest was ifyou decrease the of solute what happens to the water potential What is transpiration Evaporation of water through plants esp leaves What causes guttation Water ow into root cortex generating root pressure Water loss is regulated by GUARD CELLS K ions move in a cellTRUE Buds can form everywhere except ROOTS INSIDE TO OUTSIDE ORDER 1 hartwood 2 sapwood 3 phloem 4 periderm phloem transports sugarorganic compounds parenchyma are all of the following except Thin Flexible Lack secondary cell wall Not involved in much metabolism or synthesis this is the correct answer because it is the only one that is not true ofparenchyma cells Vascular and cork cambium produce2ndary plant body When you were 7 you built a birdhouse in a tree at 7 feet in height The tree grows a food a year How high is the bird house after 20 years Same place as the original spot The water potential in a root is 15 we put this root in a 01 M sucrose sltn water potential 1net h20 ow would BE FROM SUCROSE SLTN TO TISSUE Sieve tubein phloem and transports carbohydrates The transpirationcohesiontension mechanism Water is pulled upward over great distances by negative pressure tension in xylem What is the best type of day for water transportation when stomata are open WARM MOIST Xylem transportsWATER Periderm is what Secondary plant s body protective covering Consists of the cork cambium plusthe layers of cork cells it produces 15 kPA in tissue 32 kPA sucrose sltn and water goes where WATER GOES FROM TISSUE TO SUCROSE Cortex is ground tissue external to vascular tissue You nail a birdhouse 7 ft above the ground and 2 inches into the tree then ten years later you come backwhere is the bird house Same height but further in the tree ParenchymaALIVE AT MATURITY and carry out most of the metabolism The vascular systemtransports materials btwn roots and shoots Cells without nucleussieve tube Primary photosynthetic cellsPARENCHYMA Location of cortex OUTER FACE OF PRIMARY PHLOEM Symplastic route is through the PLASMODESMATA Apoplastic route watersolutes move along continuum of cell walls and extracellular space Symplastic routewatersolutes move along continuum of cytosol requires crossing ofa plasma membrane Transmembrane routewatersolutes move out of one cell across cell wall and into neighboring cell which may pass them the same way to the next cell Closing of stomataslowing rate of transpiration and loss of K In ux of K into cell causes water potential to decrease which encourages h20 to enter and open the stomata TRUE VASCULAR CAMBIUM gives rise to secondary phloem Point at which leafjoins nodePETIOLE Guttation is caused by ROOT PRESSURE Plants get most of their biomass from CARBON DIOXIDE COZ VESSEL ELEMENTS and TRACHEIDS XYLEM causes the transpiration cohension tension mechanism in plants A simple leafsingle undivided leaf A compound leafa blade that has multiple lea ets and no axillary bud at base Double compound leafeach lea et is divided into smaller lea ets Photosynthesis takes place in specialized PARENCHYMA cells called MESOPHYLL Dead cells at maturity Tracheid and vessel elements order when moving from pith to epidermis start primary xylem secondary xylem vascular cambium secondary phloem primary phloem plant placed in sltn with higher water potential will gain water and become turgid parenchyma cells do not have a secondary cell wall hyphae functionfood storage and obtain nutrients IRON is a micronutrient NITROGEN IS A MACRONUTRIENT Carpellate owers produce fruit The OVULE produces the female gametophyte AMMONIFICATIONconversion ofN to NH4 ammonium Figure 3618 order in which pressure ow occurs in sieve tube Unique to endosperm in angiosperm TRIPLOID DIOECIOUS plant cant reproduce on its own C h a pte r 3 3 Invertebrates 4202012 14100 PM Most Recent Hypothesis About Animal Phylogeny fig 3 211 o Metazoa no tissues 0 Eumetazoa true animals tissue layers 0 Bilateria bilateral and asymmetrical animals that includes everything else Concept 331 Sponges are basal animals that lack true tissues 0 Porifera Phyla Calcarea and Silicea Live in both fresh and marine waters 0 0 Lack true tissues and organs 0 Asymmetrical body 0 Porifera get their names because of all of the pores they have works for them in the way they get their resources Sponges o Sponges are suspension feeders capture food particles suspended in the water that passes through their body 0 Water is drawn through the pores into a central cavity the spongocoel and then ows out of the sponge through a larger opening called the osculum 0 Most sponges are hermaphrodites they function first as one seX and then as the other 0 No tissue layers 0 Filter water passing through their bodies 0 However they have main cell types 0 Choanocytequotcollar cells lining the interior of the spongocoel trap food and ingest it by phagocytosis pass it along to amoebocytes o Amoebocyte transport nutrients to other cells secretes spicules they also can transform into any other type of sponge cell allows the sponge to become exible and change shape due to changes in its environment 0 m doughnut shaped cells that span the body wall 0 Choanocytes line the spongocoel movement of agella sends up water ow Clicker Question Water movement through a sponge would follow what path 1 Poregtspongocoelgtosculum Blastoporegt gastrovascular cavitygt protostome Choanocytegt mesohylgt spongooel PSN J P0regt Choanocytegt mesohyl Concept 332 Cnidarians are an ancient phylum of eumetazoans Cnidarians o Awide range of sessile sit still attached to a substrate and oating forms including jellyfish corals and hydras 0 Simple diploblastic radial body plan with nervous system generated all throughout the body 0 Body plan is a sac with a central gastrovascular cavity 0 Single opening serves as both mouth and anus o Mesoglea layer between epidermis and endodermis gastrodermis Cnidarian Body Plans 0 Polyp form is generally sessile o Medusa form moves freely in water by passive drifting and contractions of the bell tentacles dangle down into the water and mouth faces water mobile oat through water 0 Both forms have 2 tissue layers outer endodermis and inner gastrovascular cavity and the layer in between the two is the mesoglea Defining Feature of Cnidarians o Cnidocytes 0 Unique cells that function in defense and the capture of prey 0 Contain capsulelike organelles that are capable of exploding outward o Specialized cnidae called nematocysts contain a stinging thread that can penetrate the body wall of the prey o Stimulus causes the cell to every releasing thread this is what causes stinging pain from a jellyfish 0 Some cnidocytes sting others just entangle prey Cnidarian Diversity 0 Class Hydrozoa mostly marine include both polyp feeding stage and medusa stage mobile stage in life cycle include hydras Portuguese manofwar o Hydras unusual hydrozoans in that they only exist in polyp form 0 Class Sgyphozoan all marine polyp stage reduced freeswimming medusa include jellies 0 Class Cubozoa all marine boxshaped medusa include sea wasps boxjellies 0 Strong swimmers less likely to be found near shore 0 Have complex eyes embedded in the fringe of their medusae 0 Class Anthozoa ower animals all marine medusa stage completely absent most sessile many colonial include sea anemones most corals sea fans 0 Many species secrete a hard external skeleton of calcium carbonate 0 Coral reefs provide habitat for many other species Reproductive Feeding Poly 1 polyp 39 7 713 2 r Medusa V bucl Gonad J 1 I 7 5 Medusa fr 39W SEXUAL E99 3 Sperm REPRODUCTION ASEXUAL a REPRODUCTION Portion ol BUDDING a colony ol polyps I J y i Developing polyp Mature col 9 39 39 y a 39 Planula larval 1 g Haploldln Dlplold2n The life cycle of the hydrozoan Obelia 1 A colony ofinterconnected polyps inset LM results from asexual reproduction by budding 2 Some ofthe colony s polyps equipped with tentacles are specialized for feeding 3 Other polyps specialized for reproduction lack tentacles and produce tiny medusae by asexual budding 4 Medusae swim off grow and reproduce sexually 5 The zygote develops into a solid ciliated larva called a planula 6 The planula eventually settles and develops into a new polyp Clicker Question Which of the following animals is responsible for more lethal attacks on humans each year 1 Sharks 2 Killer whales 3 Snakes 4 Cubozoans Clicker Question How many planes through the central axis will divide an organism with radial symmetry into roughly equal halves 1 1 2 4 3 10 4 Many radial symmetry animals have a round cylinder shaped body plan so there are an infant number ofplanes we can divide it as long as it goes through that central axis but for a bilateral symmetric body plan only 1 plane will cut it into 2 equal halves gives us a front end and back end Conce t 333 Lo hotrochozoans a clade identified b molecular data have the widest ran e of animal bod forms o Bilateria show cephalization they have a head and 3 tissue layers ANCESTRAL PROTIST Common ancestor of all animals Flatworms Calcarea and Silicea quotm Cnidaria quot MJ Lophotrochozoa quott Ecdysozoa eomamna system Deuterostomi o Phlym Platyhelminthes literally means quot atwormquot o Triploblastic 3 tissue layers outer ectoderm inner endoderm that lines digestive cavity and have a mesoderm in between those development but acoelomate don t have a coelom an additional body cavity 0 Early in evolutionary history they separated into two lineages O O Catenulida live in freshwater habitats reproduce asexually Rhabditophora live in freshwater amp marine waters 0 Class Turbellaria planarians O O O O O Lightsensitive eyesp ots Centralized nerve net with anterior ganglia Show some cephalization bilateral Gastrovascular cavity with 2way pharynx Most marine some freshwater predators and scavengers body surface ciliates include mostly livingfree atworms I Blood uke Schistosoma mansoni Class Monogenea 0 Marine and freshwater parasites most infect external surfaces of fishes ciliated Tapeworms 0 Class Cestoda o ScoleX has suckers and hooks that attaches to the host lining 0fintestines when consumed from undercooked food life cycle has 1 or more intermediate hosts 0 Proglottids are the reproductive structures produce eggs younger proglottids have all the reproductive organs 0 Proglottids break off after fertilization and are released in the feces which will then be picked up by another host 0 A human acquires larvae by eating undercooked meat containing the cysts and the worms develop into mature adults within the human Clicker Question Sponge Bob is a member ofwhat quotphylumquot Porifera Clicker Question Cnidarians use to immobilize or tap prey Cnidocytes Rotifers Phylum Rotifera Time animals that inhabit freshwater marine and damp soil habitats Alimentary canal with separate mouth and anus different from cnidarians and flatworms Psuedocoelomate internal organs lie within this Reproduce by parthenogenesis asexual reproduction species consist only of females that produce more females from unfertilized eggs Phylum Mollusca Most mollusks have an open circulatory system Heart pumps hemolymph through arteries and into sinuses o Radula rasplike feeding organ scraps and scoops food items Bodies have three main parts 0 m used for movement 0 Visceral mass most internal organs 0 Mantle fold of tissue over visceral mass secreting a shell Snails slugs oysters clams octopuses and squids Class Polyplacophora o Aka Chitons marine animals clinging to rocks along the shore during low tide 0 Shell has 8 plates 0 Foot used for locomotion o Radula scrape algae off the rock surface 0 No true head Class Gastropoda o Snails and slugs 0 Marine and freshwater o Asymmetrical body usually with a coiled shell 0 Result of torsion rotation of the visceral mass 0 Foot for locomotion o Radula graze algae or plants or o Undergo a distinctive developmental process torsion 0 Result because of torsion twisting of the visceral mass during embryonic development the digestive tract is coiled and the anus is near the anterior end of the animal This should not be mistaken for the formation of a coiled shell a whole separate process Class Bivalvia o Clams mussels scallops oysters o Flattened shell with 2 halves 0 Head reduced no distinct head 0 Have eyes and sensory tentacles along the outer edge of the mantle o Paired gills o No radula 0 Mostly suspension feeders Class Cephalopoda o Squids octopods cuttlefish chambered nautili Active marine predators use their tentacles to grasp prey which they can then bite with beaklike jaws and immobilize with a poison present in their saliva Head surrounded by grasping tentacles 0 Usually with suckers Shell may be external internal or absent Closed circulatory system blood remains separate from uid in the body cavity Well developed sense organs and a complex brain Clicker Question Which of the following combinations of phyla and characteristics is incorrect Porifera gastrovascular cavity two tissue layers Phylum Annelida Anatomy of an Annelid eg Earthworm 0 Body is divided into segments 0 Each segment has a set of muscles 0 Contract against coelomic uid hydrostatic skeleton Closed circulatory system with 5 pumping vessels hearts Alimentary canal with specialized regions Metaneghridum excretory tubes that remove wastes from blood and coelomic uid Cerebral ganglia functions as a rudimentary brain Ventral never chord with segmented ganglia Annelids came up several times during the test can t remember why just remember thinking quotfuck I don t remember what a goddamn annelid is Figure 3 32 2 Annelid Diversity able 334 Classes of Phylum Annelida Class and Examples Main Characteristics Oligochacm freshwater marine Reduced head no and terrestrial segmented purapodia but chaemc worms such as earthworms present see Figure 3323 Polychacla mostly marine Wclldcvelopcd head segmented worms see each segment usually has Figure 3324 parapodia with chucme Lubedwelling and free living Hirudinea leeches sec Body usually flattened Figure 3325 wile reduced coclom and segmentation chaetae absent suckers at anterior and posterior ends parashes predators and scavengers Hirudinea leeches body usually attened with reduced coelom and segmentation chaetae absent suckers at anterior and posterior ends parasites predators and scavengers Polychaetes mostly marine segmented worms well developed head each segment usually has parapodia with chaetae tubedwelling and freeliving Oligochaete freshwater marine and terrestrial segmented worms such as earthworms reduced head no parapodia but chaetae present far fewer per segment than in polychaetes Concept 334 Ecdysozoans are the most species rich animal group Calcarea andSilicea Wm ANCESTRAL Cnldarla PHOTIST n1 C Common g Lophotrochozoa 391 ancestor of g all animals 3 E Ecdysozoa quot E gt H ID 2 N WW as Phylum Arthropo da 2 out of every 3 known species of animals are arthropods Table 3quot 5 Subphyla of Phylum Arthropo Subphylum and Examples Main Characteristics Chalice nlonncs horstshoc mt sispl criscorpiuns scc Figures appendages chcllcumc 3330 313 Myriap A null csmipc 5 sci 3333 and 333 l lt XLIpmla insects springmils 37 Ste Figures 33735 33 l Cmslncca lambs lobsters n L smml su Figures 3329 and 33 38 Body hzwmg one or No m39lin parts six pairs ol pcdlpzllps and four pulls 39 k CilL S and stlinci hch bearing Flg urts 39 IHlCnl liIC lll l L WHP mmnhpnns lurcsxrml milli pulus ue lxurbivomus and have 390 pairs of walking lugs pcrmlnk scgmc ccnupcclcs ul t carnivorous Ll have om pnir of walking legs 7H trunk scgmcnl an JDlSOl l Cl 393 ln rst body scgmcnl Body clmdcd Inlu head thorn and a domcn In the or L39 or lnppuig three pairs 0 1th 1 Ll unlly two pflllS of Wings mostly L ITCSI rizl Ilutly ol l39n or llu39c parts amen lIIL preset chewing h a mum rm 0 x on airs all mostly mamm zlnd mlmnlcr General Characteristics of Arthropods Arthropod body is covered by the cuticle an exoskeleton made of chitin When an arthropod grows it sheds the exoskeleton by a process called ecdysis Arthropods have an open circulatory system Hemolymph is circulated into spaces surrounding tissues Variety of gas exchange organs 0 Gills aquatic species have gills with thin feathery extensions that place an extensive surface area in contact with the surrounding water 0 Tracheal tubes most insects have these branched air ducts leading into the interior from pores in the cuticle o Booklungs in most spiders stacked platelike structures contained in an internal chamber CLCIKER QUESTION In the life cycle ofa typical hydrozoan Class Hydrozoa which of the following would most likely be free swimming medusa Subphylum Cheliceriformes 0 Known for clawlike feeding appendages called chelicerae pinchers or fangs 0 Lack antenna 0 Have simple eyes eyes with a single lens Horseshoe crabs Scorpions 3quotquot I Arachnid Anatomy 0 Includes spiders scorpions ticks and mites o Bloodsucking parasites that live on the body surfaces of reptiles or mammals 0 Body has 2 regions o Cephalothorax o Abdomen o CephalothoraX has 6 pairs of appendages o Pedipalps function in sensing feeding or reproduction o Chelicerae fanglike which are equipped with poison glands to attack prey o 4 pairs ofwalking legs 0 Book lungs for respiration Stomach Intestine Spinnere s GonoPore Chelicera Pedipalp exit for eggs Sperm 8 quot gland receptacle Clicker Question 3 of the 4 animals listed below possess some type of coelom Select the exception H Annelids 2 Arthropods 3 Molluscs 4 Platyhelminths Subphylum Myriapo da Millipedes and Centipedes All are terrestrial Millipedes Class Diplopoda o 2 pairs oflegs per segment large number oflegs o Detritus feeders in leaf litter o Eats decaying matter and other plant matter 0 May have been some of the earliest animals on earth Centipedes Class Chilopoda o 1 pair oflegs per segment 0 Carnivores Subphylum Hexapoda o Insects and their relatives 0 More species rich than all other animals Insect Anatomy 0 Insects are characterized by having 3 pairs of walking legs on the thorax o 1 or 2 pairs ofwings o 3 body regions head thorax and abdomen 0 Insects have an open circulatory system with a quotheartquot that pumps hemolymph around the organs 0 Cerebral ganglion and sense organs antennae and eyes are concentrated in the head 0 Ventral nerve cord with segmented ganglia 0 Gas exchange occurs through tracheal tubes Air enters and exits through spiracles 0 Metabolic wastes are removes from hemolymph by malphigian tubules Subphylum Crustacea 0 Shrimp lobster crabs crawfish o Biramous appendages o Gills for gas exchange 0 Lobsters crayfishes crabs and shrimps decapods Concept 338 Echinoderms and chordates are deuterostomes o Echinoderms may not look like chordates which includes the vertebrates but they share a common development plan 0 Deuterostomes o Radical cleavage o Coelom develops from archenteron o Mouth forms opposite ofblastopore Phylum Echino dermata o Echinoderm spiny skin 0 Slow moving or sessile marine animals 0 Pentaradial symmetry 0 Unique watervascular system Water ows in and out of the watervascular system through the O maderporite Branching from the radial canals are the tube feet Tube feet are used for O locomotion capturing prey and attaching to substrates 0 Water vascular system consists of ring and canal and radial canals Echinoderm Diversity fig 334044 Classes of Phylum Echinodermata Class and Examples Main Characteristics Asteroidea sea stars see Stztr shapcd body with multiple Figures 3339 and 33403 arms mouth directed to substrate Ophiumidea brittle stars Distinct central disk long see Figure 334013 exible arms Ule feet lack suckers Echinoidea sea urchins Roughly spherical or disllt sand dollars see Figure shaped no arms ve rows of 33400 tube feet enable slow movement mouth ringed by complex jaw like structure Criuoidea sea lilies Feathered arms surrounding feather stars sec upwardpointing mouth Figure 31401 Holothuroidca sea Cucumbershaped body we cucumbers see rows of tube feet additional Figure 33406 tube feet modi ed as feeding tentacles reduced skeleton n0 ints Concentricycloidcn Disk shaped body ringed with sea daisies see small spines incomplete Figure 334017 digestive system live on submerged woo Summary of Animal Phyla Tahlr 33 7 521mm Ammal vhym Magma mum Ellenea mymm r km NW lm nmlhywlm u mm mm mu u 1 m I mmmn umm kammukm Iurhnldwlln mm Mmmnhh numwx mvmn w Mum luHHu LLmn um WIN Anm hnh Wm mm mm Ammlwvmw MllWVub muswm mm m 5quot hhmulanm y m m wumm um m Mm mmmm mm 7 399 x Demipxinn Dszmunhmulnumyvmm hmuw um wwn danlm mm Imuw mu m mm Hummumm Mumsundemeumllm w mm Wymum mu m mmmmu mm a We mm 3 vwmnnl y ImeL unwgmmlnl Wynan gummwbmnl mywhgmw Inn leumhmmn MM Jhuvwm mm WMM ummmummmwmuwwmum haul mm mm Maw mm mm maummm mm mm uan mm mm wwwwm Mth mm Mm mmimm wrm menlmymmmman vumlmm mva N nmmhwl Hm hm hm M W m mm mm lwhvmmwllhllj Mlhmimlmuhmm mwwlwulwumwmnm mum quotle umlwudmw mwluMilk Wanda mummy mm mm wuhxwuvmm My ymw Arm byxMJmukmuwrulmumquotml mm Man wth mm aruwrm um mum Nulmmn Naurume W mumm Wmv m vmu hnrd duNLIMM tramum phnmmldm mm Mum Chapter 34 Vertebrates 4202012 14100 PM Chordate Phylogeny Clicker Question Which of the following statements is not true 1 All chordates have notochords All Chordates have pharyngeal pouches All Chordates have a postanal tail vFWN All chordates have vertebrae Concept 341 Chordates have a notochord and a dorsalI hollow nerve chord o Chordates are deuterostome bilaterian animals 0 2 chordate subphyla are invertebrates o Urochordata o Cephalochordate o 3ml subphylum Craniata includes the Vertebrates Derived Characters of Chordates o All chordates share 4 derived characters 0 Notochord a dorsal hollow nerve cord pharyngeal slits or clefts and a muscular post anal tail I Notochord longitudinal exible rod located between the digestive tube and the nerve cord provides skeletal support throughout most of the length ofa chordate provides a firm but exible structure against which muscles can work during swimming I Dorsal Hollow Nerve Cord develops from a plate of ectoderm that rolls into a tube located dorsal to the notochord unique to Chordates I Pharyngeal Slits or Clefts located on the pharynx allow water entering the mouth to exit the body without passing through the entire digestive tract used for suspension feeding or gas exchanges gill slits I Muscular Post Anal Tail a tail that extends posterior to the anus contains skeletal elements and muscles to help propel many aquatic species 0 Although some species possess some of these traits only during embryonic development Tunicates o Subphylum Urochodata Sessile marine suspension feeders o Draws water in through incurrent siphon filtering food particles exiting through the excurrent siphon Tunicates possess the chordate characteristics during their larval stage 0 Once a tunicate has settles on a substrate it undergoes a radical metamorphosis stage in which many ofits chordate characters disappear tail notochord and nervous system all go away Lancelets Subphylum Cephalochordata Maine suspension feeders Retain chordate features throughout lifespan Clicker Question Which of the owing is a diagnostic feature of tunicates that forms the basis for its classification as a chordate 1 FSNEquot Metamorphosis from a motile larva to a sessile adult A heart that allows circulation of blood A notochord located along the dorsal part of the larva Sexual reproduction during the larval stage Concept 342 Craniates are chordates that have a head Hagfish Subphylum Craniata The origin of the head in chordates allowed some to become active predators Shared characters in craniates o Cranium 0 Brain 0 Eyes and other sensory organs Craniates posses two or more sets of Hox genes lancelets and tunicates only have one set Unique feature of craniates a neural crest collection of cells that appears near the dorsal margins of the closing neural tube in an embryo these cells disperse throughout the body where they give rise to a variety of structures including teeth some of the bones and cartilage of the skull the inner layer of skin dermis of the facial region several types ofneurons and the sensory capsules in which eyes and other sense organs develop In aquatic craniates pharyngeal clefts evolved into gill slits pumping water through slits can assist in sucking in food and gas exchange 0 Class MyXini o The least derived extant species of Craniate o Iawless marine craniates o Cartilaginous skull and axial rod derived from notochord o No vertebrae Concept 343 Vertebrates are craniates that have a backbone 0 They have 0 Vertebrae enclosing a spinal chord 0 An elaborate skull o Fin rays in aquatic forms Lampreys Class Petromyzontida Oldest living lineage of vertebrates Parasites that feed by clamping their round jawless mouth onto the ank ofa live fish then penetrating with their tongue to suck blood Vertebrae are cartilaginous segments surrounding the notochord and arching partly over the nerve chord Cartilage contains no collagen lawless have a suckerlike mouth and teeth 0 Found in marine and freshwater Origins of Bone and Teeth o Mineralization appears to have originates with vertebrate mouthparts o Conodonts quotcone teeth were 1st with mineralized mouth and pharyngeal parts 0 Ostracoderms had mineralized plats on their skin 0 Endoskeleton became mineralized later Clicker Question The most primitive but still eXisting craniates are members of the class 1 MyXini 2 Petromyzontida 3 Chondrichthyes 4 Osteichthyes Concept 344 Gnathostomes are vertebrates that have jaws o The most successful group ofvertebrates alive today Derived Characters of Gnathostomes jaw mouth o laws 0 Evolved from skeleton supports of the pharyngeal slits 0 Enhanced sensory system including lateral line system 0 Lateral line system organs that form a row along each side of the body and are sensitive to vibrations in the surrounding water 0 Mineralized endoskeleton o Paired appendages Chondrichthyans Sharks Rays and Their Relatives 0 Class Chondrichthyes quotcartilage fish 0 Includes sharks rays and ratfishes o Sharks are streamlines and swift swimmer but do not maneuver well 0 Rays are dorsoventrally attened 0 Skeleton composed predominantly of cartilage though often impregnated with calcium RayFinned Fishes and LobeFins 0 Most vertebrates belong to a clade called Osteichthyes quotbony fish 0 Including ourselves 0 Have bony endoskeleton with a hard matrix of calcium phosphate 0 Aquatic osteichtyans o Vertebrates we call fishes RayFinned Fishes 0 Class Actinopterygii o Familiar aquatic osteichthyans o Fins supported by long exible rays 0 Nemo lives in anemones sea horse moray eel 0 Serve as a major protein source for humans Lobe Fins o Sarcopterygii o Rodshaped bones surrounded by muscle in pectoral and pelvic fins 0 Class Actinistia coelacanths 0 Class Dipnoi lungfishes Clicker Question New body features don t usually appear quotfrom scratch but result from the modification of existing features to serve other functions What feature became modified to form jaws 1 The cranium 2 The primitive forelimbs 3 Gill arches 4 The notochord Clicker Question Sharks skates and rays belong to the class 1 Reptilian Chondrichthyes Sarcopterygii gts Actinopterygii Concept 345 Tetrapods are gnathostomes that have limbs Derived Characters of Tetrapods o 4 limbs and feet with digits 0 in some forelimbs are modified for grasping bipeds or ight eg birds 0 the head is separated from the body by a neck that originally had one vertebrae on which the skull could move up and down Later it could then movie side to side 0 Ears for detecting airborne sounds o No lateral line system Origin of Tetrapods fig 3421 0 Based on fossil discoveries Amphibians 0 Class Amphibia 0 Order Urodela salamanders retain their tail as adults 0 Order Anura frogs and toads lack tails as adults specialized for mobility on land skin is covered in a layer of distasteful or poisonous mucus to help avoid being eaten by larger animals 0 Order Apoda caecilians legless and nearly blind resemble earthworms o Moist skin that complements lungs in gas exchange 0 Amphibian means two lives 0 Live between aquatic and terrestrial habitats o Tied to water for reproduction 0 Eggs desiccate out ofwater o Larvae are often aquatic Clicker Question If an amphibian could be a plant which plant would it be 1 Monocot 2 Moss need water for reproduction 3 Cycad 4 Gnetophyte Concept 346 Amniotes are tetrapo ds that have terrestrially adopted eggs 0 Amniotes include the reptiles birds and the synapsids lineage leading to the mammals Derived Characters of Amniotes o Amniotes get their name from the amniotic egg 0 Egg with specialized membranes that protect the embryo I Amnion protects the embryo in a uidfilled cavity that cushions against mechanical shock Chorion the chorion and the membrane of the allantois exchange gases between the embryo and the air Oxygen and carbon dioxide diffuse freely across the shell Yolk sac contains the yolk a stockpile of nutritents Blood vessels in the yolk sac membrane transport nutrients from the yolk into the embryo Other nutrients are stored in the albumen quotegg white I Allantois a disposal sac for certain metabolic wastes produced by the embryo The membrane of the allantois also functions with the chorion as a respiratory organ 0 Relatively impermeable skin prevent water from getting out 0 Ability to use rib cage to ventilate the lungs O Amnion protects the embryo in a uidfilled cavity allowed amniots to move out and colonize a wide range of terrestrial habitats O Allantois disposal sac for certain metabolic wastes Also functions with chorion as a respiratory organ 0 Chorion exchanges gases between embryo and the air 0 Yolk sac provides nutrients for the developed embryo Clicker Question Why is the amniotic egg considered an important evolutionary breakthrough It 1 Has a shell that increases gas exchange 2 Allows incubation of eggs in a terrestrial environment 3 Prolongs embryonic development 4 Provides insulation to conserve heat energy Reptiles o The reptile clade includes the tuatara lizards snakes turtles crocodilians birds and the extinct dinosaurs 0 Have scales that create a waterproofbarrier 0 Lay shelled eggs on land 0 Mostly ectothermic o Absorb external heat as the main source ofbody heat 0 Exception is the birds which are endothermic heat through metabolic activity Turtles 0 The most distinctive group of reptiles alive today 0 All turtles have a boxlike shell made of upper and lower shields that are fused to the vertebrae clavicles collar bones and ribs Lepidosaurs 0 Two lineages oflepidosaurs o Tuataras can live to be 100 years old 0 Squamates o Tuataras lizardlike reptiles o Squamates include the lizards and snakes Archosaurs 0 Includes the Dinosaurs extinct and the living Crocodilians and Birds Birds 0 Birds are Saurischian Archosaurs 0 But their anatomy has undergone modification in their adaptation for ight o No urinary bladder Females have 1 ovary Males and females have small gonads Light skull and no teeth I These are all adaptation to reduce weight Adaptation for Flight 0 Most obvious adaptations for ight are the wings and feathers O O 0 Concept 347 Mammals are amniots that have hair and produce milk Derived Characters of Mammals o Mammary glands that produce milk 0 Hair and insulating layer of fat beneath skin 0 Endothermic o Diaphragm to help ventilate the lungs 0 Generally larger brain that other vertebrates of equivalent size 0 Extended care period for the young 0 Differentiation of teeth 0 Four chambered heart Early Evolution of Mammals o Mammals evolved from synapsid reptiles o Modification of the jaw bones is distinctive in mammals Clicker Question Which is not characteristic of all mammals 1 A fourchamber heart 2 Have hair at some period of their life 3 Have glands to produce milk to nourish their offspring 4 Give birth to live young viviparous Monotremes 0 Includes the platypus and spiny anteater 0 Lay leathery eggs 0 Nourish young with milk but no nipples 0 Instead of nipples they have glands on the belly which the baby sucks Marsupials 0 Includes opossums kangaroos koalas 0 Young are born very early in development and crawl to marsupium pouch 0 Development is completed within the pouch Eutherians Placental Mammals o Eutherians have a longer period ofpregnancy o Eutherians complete embryonic development within a uterus joined to the mother by a placenta Clicker Question Below are taxonomic categories matched with a common name of an animal Which of these is incorrectly matched Dipnoi lungfish Actinopterygii rayfinned fish Apoda caecilians rFWNH Archosauria lizards and snakes C h a pte r 40 Basic Principles of Animal Form amp Function4202012 14100 PM Concept 401 Animal form and function are correlated to all levels of organization 0 Physical laws especially physics of exchanging materials with environment limits range of animal forms Exchange in Simple Organisms o Singlecelled organisms 0 Exchange material by diffusion o Entire plasma membrane is exposed to medium 0 Multicellular organisms with a sac body plan 0 Body wall is only 2 celllayers thick 0 Exchange is by diffusion Exchange in Complex Animals 0 Large complex animals have highly folded or branched internal surfaces specialized for exchanging materials 0 This increases surface area 0 These exchange surfaces are usually internal but are connected to the environment Via openings on the body surface the mouth for example Clicker Question The organization of the animal body involves a hierarchy of structures The correct order of this hierarchy from least to most complex is 1 Cells organs tissues organ system 2 Tissues cells organ systems organs 3 Organs tissues cells organ systems 4 Cells tissues organs organ systems Epithelial Tissue 0 Covers the outside of the body and lines the organs and cavities within the body 0 Cells are closely joined EPITHELIAL CELLS Columnar epithella whlch have cells with relatively large cytoplasmle volumes are olten located where secretion or active absorption of substances is an important lunctiop A stratified columnquot epnheuum A simple columnar ephhollmn pundostratillad culated cotumntv epithelium Connective Tissue 0 Functions mainly to bind and support other tissues 0 Composed of sparsely packed cells scattered throughout an extracellular matrix 0 Major types 0 Loose connective tissue tissue layer beneath your skin collagen and elastic fibers tissue that covers the organs stretchy makes your skin pull away from body Adipose tissue stores fats as a source of energy and maintains body 0 temps Fibrous connective tissue makes up things like the tendons connects 0 muscle to bone densly pact collagen fibers tough and rigid that withstands the force of muscles pulling against the bone Cartilage found between bones that provide a cushioning between the 2 O bones shock absorption at those joints Bone more solid than the cartilage but still living tissue ostiocites cells 0 living within the bone that gives bones its strength Blood has blood cells dispersed without the extracellular matrix carries 0 nutrients and oxygen Muscle Tissue o Composed oflong cells called muscle fibers capable of contracting in response to nerve signals 0 3 types 0 skeletal responsible for our movement under voluntary control 0 cardiac makes up the bulk of the heart when contracting it provides the force necessary to provide blood throughout the body response to the requirements for our blood circulating throughout the body involuntary o smooth surrounds organs like digestive tract and blood vessels involuntary control Nervous Tissue o 2 types 0 neurons basic units of nervous system 0 glia help nourish insulate and replenish neurons 0 Sense stimuli and transmits signals throughout the animal 0 Nerve cell responsible for receiving and transmitting is the neuron Organ Systems 0 Organ systems carry out the major body functions ofmost animals Main Components and Functions in Mammals Table 401 Organ System Th Organ System Digestive CML IXIJKUI Respimiow lllllhllllv md iymplmiiv Buttery Endocrine Ru p mdiict l 39 Nervous Inii giimcniziry SlickLil MUSL39 ulir Main Components esophagus siunincli 3illlCI L39lS u S hluml Lungs miclim other brmihing luhti iiimc mamm lymph mills iliymus splu39n mpl c cls viiiic blood culls Kidncys iircicrs unnir39 bladder umlim Pilinlilq llI39rlld p ImrimmuScciciiiig h quot ms iiilwr d5 r Gum39s icsics inil Iswcuicil organs Brain spinal cord ntrvas sensory organs Skin and IIS llcl ll illIVCS such 15 her laws skin glands Slwlrimi hums lt nd fu lig iuncnis cill1llllg l Skulrml musdrs Main Functions Fund processing ungcsiiun LligcsuoiL ilisurpimn climininion liiicmul llbll llmilam ol niiicnils Gus exchange Upka of oxygen disposal ul carbon dioxide and defmsc liglllln minlions and czinccrl Disposal nl metabolic wastes rcgiiliiini ul usimviii lmLimc l M I nod Cimrdinaiinn oi body aciWiliL S such as dgL Slli n mL39lJlmllsml chmdiiciion Cniudinaiion of body JL39UVUICS chlccnim ol Fllmull md lnimulmmn ul rusponsce iul ium l mlc ion ngmnsi mechanical injuiy iillrcuon drying I uul llivi39mun iilmn kuin bllplk l39l pmimion of iiiicmni organs unwilqu Movemcm lurumiiliun Control and Coordination 0 Animals need to coordinate activities among organs 0 Two systems responsible o Endocrine slow response but long lasting signaling molecules released into the bloodstream by endocrine cells reach all locations in the body well suited for coordinating gradual changes such as growth and development reproduction metabolic processes and digestion Nervous quick response but short lived neurons transmit signals called 0 nerve impulses between specific locations in the body well suited for directing immediate and rapid responses to the environment especially fast locomotion and behavior I both systems use the same type ofpathway to transfer signals Concept 402 Feedback control maintains the internal environment in many animals 0 Interstitial uid uid that fills spaces between cells 0 Internal environment 0 Exchange occurs with cells here 0 Homeostasis maintaining internal variables within an acceptable range Regulating and Conforming o Regulator uses internal control mechanisms to moderate internal change in the face of external uctuation o Conformer allows internal conditions to vary with certain external changes 0 River otter keeps its body temperature that is largely independent of that of the water in which it swims o Largemouth bass conforms the temperature of the lake it inhabits 4D lver otter endotherm 5 Body temperature 5390 7N 39 D 1 0 2b 30 no Ambi n e iim Bi a l meme21mm C 0 Clicker Question The organism in which these measurements were made is an osmo and a thermal 1 Conformer regulator 2 Regulator conformer 3 Conformer conformer 4 Regulator regulator Mechanisms of Homeostasis o Homeostatic control systems have 3 functional components 0 Receptor send signals to control center brain 0 control center 0 effector responds to the stimulus Response produced Heater lu rned of Se point Set point Response Heat produced Negative Feedback 0 Response to change is to counteract the change resulting in a return to the original condition 0 quotNegativequot because it negates the initial change Thermostal In hypothalamus activates coolbng mechanisms Sweat glands secrete sweat hm evaporales coollng the body aiaod vessels In sknn dllale 39 lt cnplllrlns ml with warm blood heat radiates tram Blood vessels in skin conslrlcl dlverllng blood lrom skln to deeper tissues and reducing heat loss from skin su ace Tharmcmtal in 39 hypothalamus Hquot activates Skeletai muscles rapidly W rm39nEl conlruclcaus ing ablverina mechanisms whlch genomles heat Positive Feedback o Intensifies the original change when the need exists 0 Drives events to a conclusion 0 Tends to be self limiting During childbirth the pressure of the baby s head against receptors near the opening of the mother s uterus stimulates the uterus to contract These contractions result in greater pressure against the opening of the uterus heightening the contractions and thereby causing even greater pressure until the baby is born Clicker Question Which of the following is the correct sequence involved in the regulation of homeostasis 1 Stimulusreceptorcontrolcenterresponseeffector Stimulusresponsecontrol centerreceptoreffector Stimulusreceptorcontrol centereffectorresponse FSNN Stimuluscontrol centerreceptoreffectorresponse Concept 403 l39 quot processes for thermu 39 involve form function and behavior 0 Thermoregulation process by which animals maintain an internal temperature within a tolerable range Ectotherms use environmental energy and behavioral adaptations to regulate body temperature 0 Endotherms use metabolic heat to regulate body temperature Ectotherms and Endotherms o Ectotherms eg most invertebrates fishes amphibians and nonbird reptiles o Endotherms eg birds and mammals Clicker Question Hypertension produces damage to the lining of the arterioles of the kidneys which results in the release ofmolecules that will further raise blood pressure This is an example ofan 1 Negative feedbackloop 2 Positive feedback loop positive because it s building on itself 3 Controlling mechanism 4 Uncontrolled mechanism Modes of Heat Exchange 0 Radiation the emission of electromagnetic waves by all objects warmer than absolute zero Here a lizard absorbs heat radiating from the distant sun and radiates a smaller amount of energy to the surrounding air Evaporation the removal of heat from the surface of a liquid that is losing some of its molecules as gas Evaporation of water from a lizard s moist surfaces that are exposed to the environment has a strong cooling effect Convection has to do with air or water moving past an organism transfer of heat by the movement of air or liquid past a surface as when a breeze contributes to heat loss from a lizard s dry skin or when blood moves heat from the body core to the extremities Conduction heat being transferred between 2 solid surfaces being in contact with each other lizard sitting on a rock the direct transfer of thermal motion heat between molecules of objects in contact with each other as when a lizard sits on a hot rock Balancing Heat Loss and Gain 0 Insulation reduces ow of heat between an animal and its environment 0 Includes feathers fur blubber skin 0 Circulatory adaptations o Vasodilation blood ow to the skin increases facilitating heat loss 0 Vasoconstriction blood ow to the skin decreases lowering heat loss through convection and conduction 0 Counter current exchange have 2 vessels that are running antiparallel to one another see this in the leg of a Canada goose with it s feet down in the snow the external temperature can bring the blood of the leg so it has the counter current exchange where the artery going down to the vein runs parallel with the vain running up through the body which are in close proximity heat transferred to the vain and by the time it reaches the body it s around normal body temperature also in arrangement in vessels of marine animals Cooling by Evaporative Heat Loss 0 Evaporation from a surface causes heat loss 0 Sweating carries heat away from skin surface lowering body temperature 0 Panting dogs have some sweat glands so when it gets hot it starts panting which causes the evaporative cooling evaporation from the inside of the mouth and tongue helps to cool down the surface and the blood around the mouth circulating the dog 0 Bathing an elephant splashes water on their body to allow for the evaporative cooling that helps to lower the body temperature Other Behavioral Responses 0 Basking in the sun and moving in the shade o Maintaining a certain posture Clicker Question Which of the following animals would the percent ofits energy budget spent for homeostatic control he the largest 1 A marine jellyfish A snake in a temperate forest A desert insect H SNN An arctic bird Concept 404 Energy reguirements are related to animal sizeI activityI and environment 0 Bioenergetics the ow of energy through an animal dependent upon animal size how active they are and the environment that the animal lives in Energy Sources and Allocation 0 Animals harvest chemical energy from food 0 Energy containing molecules are broken down to make ATP 0 Once energetic needs are met remaining molecules are used in biosynthesis Organic molecules in f d External environment A ninmal body Digestion and mm lost in feces Nutrient molecules in body cells Ener y lost in urine Carbon Cellular W Biosynthesls gro h storage and reproduction Cellular h A Hea work Heat Quantifying Energy Use 0 Metabolic rate the amount of energy an animal uses in a unit of time 0 Can be measured by the amount of oxygen consumed or carbon dioxide produced by an organism Size and Metabolic Rate 0 What we see is that small animals have a low metabolic rate and as we increase the body size the metabolic rate goes up with the body mass 0 Ifwe scale the metabolic weight with the kilograms of an animal it s the reverse pound for pound a mouse will have a higher metabolic rate than an elephant this is because maintenance of thermal regulation needs a higher metabolic rate per unit mass to maintain that high body temperature an elephant can maintain it s body heat more efficiently Reproduction 500000 Annual energy expandllm kcallyr l 60 kg lama human 4kg male Adena nenguin anskg emale deer Hg lemaleyymnm I 39 1mm Australia Tova annual energy expendilures Norquot America 433 Energy expenditure per unll mans kcallkgday b sway manure W W mass runway Minimum Metabolic Rate and Thermoregulation o Basal metabolic rate BMR metabolic rate of an endotherm at rest 0 Standard metabolic rate SMR metabolic rate of an ectotherm at rest 0 Different because endotherms maintain such a high metabolic rate all the time The body tissue that consists largely of material located outside of cells is o Connective tissue 0 Epithelial tissue 0 Skeletal tissue 0 Smooth tissue 0 Nervous tissue Which of the following would increase the rate of heat exchanged between an animal and its environment 0 Feathers or fur o Vasoconstriction 0 Wind blowing across the body surface 0 Countercurrent heat exchanger 0 Blubber or fat layer Consider the energy budget for a human an elephant a penguin a mouse and a snake The would have the highest total annual energy expenditure and the would have the highest energy expenditure per unit mass 0 Elephant mouse 0 Elephant human 0 Human penguin 0 Mouse snake 0 Penguin mouse Compared with a smaller cell a larger cell of the same shape has 0 Less surface area 0 Less surface area per unit volume 0 The same surface to volume ratio 0 A smaller average distance between its mitochondria and the external source of oxygen 0 A smaller cytoplasmtonucleus ration An animals inputs of energy and materials would exceed its outputs o If the animal is an endoderm which must always take in more energy because of its high metabolic rate 0 Ifit is actively foraging for food 0 Ifit is hibernating o If it is growing and increasing its mass Which of the following animals uses the largest percentage ofits energy budget for homeostatic regulation 0 A hydra o A marine jelly an invertebrate o A snake in a temperate forest 0 A desert insect o A desert bird C h a pte r 4 1 Animal Nutrition 4202012 14100 PM Concept 411 An Animal39s diet must supply chemical energy organic moleculesI and essential nutrients 0 Chemical energy organic molecules mostly supplied by carbohydrates proteins and lipids o Other nutrients include vitamins and minerals Essential Nutrients 0 Essential amino acids are ones that animals can39t synthesize 0 Animals require 20 amino acids 0 Complete proteins have all the essential amino acids included meat eggs cheese dairy products 0 Incomplete proteins sources ofproteins that are lacking 1 or more of the essential amino acids usually proteins taken in from plants 0 Essential fatty acids are required in the diet 0 Usually unsaturated fatty acids 0 Humans need linoleic acid Clicker Question Which choice offers the best time to measure basal metabolic rate 1 An adult at rest prior to its first meal of the day 2 A baby at rest that has just had its first meal of the day 3 A child that has only eaten a sugarfree meal 4 An adult watching TV after dinner Vitamins o Vitamins are organic molecules 0 Serve as antioxidants and coenzymes things that bind to and get rid of oxygen free radicals o 2 classes 0 Water soluble soluble in water polar covalent or ionic molecules that are able to dissolve in water and able to move through the blood can be ushed out of the body 0 Fat soluble nonpolar covalent don t dissolve in water but are transported around in fats HDLs and LDL cholesterol stored in adipose tissue and in the liver because they re stored in your body they can build up to toxic levels in the body ifyou take too many Minerals 0 Minerals are inorganic elements or compounds Clicker Question Which of the following vitamins can be stored in the bodies of animals Vitamin C Vitamin Bl Niacin uthp x Vitamin E ConceDt 412 The main stages of food m 39 are 39 absorptionI and elimination Four Stages of Food Processing 0 Ingestion food brought in through the mouth 0 Digestion 0 Mechanical breakdown physical breakdown of food 0 Chemical breakdown digestive chemicals and enzymes breakdown food breakdown large polomers to smaller monomers 0 Absorption small subunits transported out of digestive system 0 Elimination indigestible material expelled from body Intracellular Digestion hydrolysis of food inside vacuoles o Sponges are sedentary filter feeders with no specialized digestive system 0 Digestion takes place in collar cells lining waterfilled spongocoel intracellular digestion 1 Water carrying food particles enters pores 2 Food particles are filtered by collar cells 3 Food enters by endocytosis 4 Food digested by lysosome Clicker Question Which of the following possesses a gastrovascular cavity 1 Annelids 2 Platyhelminthes 3 Molluscs 4 Arthropods Extracellular Digestion o Hydra have a gastrovascular cavity 0 Opening acts as both a mouth and anus o Glad cells release enzymes and breakdown food 0 Nutritive cells absorb nutrients and food particles Indigestible material expelled out mouth 0 Digestion in a Tube is More Efficient o Alimentary canal complete digestive tract that has digestive tube with a mouth and anus o Digestive tube can be organized into specialized regions 0 Allows animals to eat more frequently Concept 413 Organs specialized for seguential stages of food processing form the mammalian digestive system Major Organs o Mouth 0 PharynX o Esophagus 0 Small intestine 0 Large intestine o Rectum o Anus Accessory Organs o Salivary glands o Secrete saliva starts the chemical digestive process in the mouth 0 Liver o Secretes bile o Gallbladder 0 Stores and concentrates the bile used to emulsify lipids that are being ingested o Pancreas o Secretes digestive enzymes that break down foods in the small intestine The Oral Cavity Pharynx and Esophagus 0 Mechanical and chemical breakdown of food begins in the mouth 0 Chewing mechanical breakdown of food by teeth 0 Salivary glands produce saliva to start chemical breakdown of food Functions of Saliva o Amylase breakdown starches into small polysaccharides and disaccharides o Bacteriakilling enzymes and antibodies 0 Initiates chemical digestion o Lubricates food helps with swallowing w o Carries food molecules to taste buds on tongue for food quality ID From Mouth to Stomach o Tongue pushes food into the pharynx initiating swallowing re ex o Tongue movements manipulate the food helping shape it into a ball bolus o Larynx moves up and tips epiglottis over the glottis o Esphoganeal sphincter releases allowing bolus to enter the esophagus o Waves of muscular contraction peristalsis moves the bolus down the esophagus to the stomach The Stomach o The stomach has 3 major functions 0 Food storage and gradual release into the small intestine 0 Mechanical breakdown of food by churning contractions 0 Chemical food breakdown by stomach gland secretions o Mixture of ingested food and digestive juice is called chyme Stomach Secretions o HCL 0 Makes stomach uid very acidic pH 2 o Secreted by parietal cells 0 Unfolds proteins in foods 0 Pepsinogen o Secreted by chief cells 0 Inactive enzyme converted into active pepsin when exposed to lICL o Pepsin breaks down proteins into small peptides o Mucus o Protects stomach wall from acid 0 Secreted by mucus cells Chapter 22 1242012 41100 AM Descent with Modification A Darwinian View of Life Evolution llh n l1 all P l o Descent of modern organisms with modi cation from preexisting organisms o All organisms are descendants ofa common ancestor A lot of common traits in life forms also a lot of diversity Evolutionam Adaptation o Accumulation of inherited characteristics traits that enhance organisms ability to survive in specific environments PreDarwin Theom of Evolution disuse of parts Example stretching giraffes o Inheritance of acquired characteristics These modifications are inherited by offspring 0 His ideas are WRONG 0 Reason Arnold Schwarzenegger spends a lot oftime getting buff but that doesn t mean that his children will be born buff Evolution by Natural Selection 0 Darwin and Wallace developed the theory independently 0 Darwin went on a 5year voyage on the Beagle as the ship s naturalist and discovered many things about organisms and evolution 0 Wallace was a naturalist who studied in Indonesia Natural Selection 0 The unequal survival and reproduction of organisms due to environmental forces resulting in the preservation of favorable adaptations 9 survival ofthe fittest 0 Process selects from what is available in the gene pool 0 New characteristics are not created on demand 0 Causes change in the gene frequencies over many generations 0 Selection comes from all ofthe variables in the gene pool 0 Mechanism behind Natural Selection Observations Individuals in a population Organisms produce more van In heritable offspr ng en the characteristics environment can support Inferences Individuals that are well suited to their environment tend to leave more offspring than other individuals and Over timel favorable traits accumulate in the population Think about the 100 m dash track and field competition How can we change this race to reflect the process of natural selection 0 Change the environment 0 Only allow winners to produce offspring o Slower ones who lose will die 9 eaten by coyotes Artificial Selection Selective breeding of organisms to encourage the occurrence of desirable traits 0 Similar to natural selection 9 we decide who survives instead of nature deciding Cabbage Selection for apical tip bud Brussel s sprouts Selectionlnr 39 Broccoli a 39 e xillary sld buds Selection for flowers and stems Selection for stems Selection for leaves Wild mustard Kohlrabi Evolution is supported by an overwhelming amount of scientific evidence FIELD STUDV aeak on name specie mulhem Florian MuseumSpecimen Ivarage Mummr or ln lvldml an ruuaaum species canrm Flmldl Soapberry bug with beak nigg rted in balloon vine fruit s 7 a r 9 in Bank length mm Soapberry bug fed on the balloon vine fruit by sucking the nutrients from the seeds Goldenrain fruit is more flat than the balloon vine so the bug didn t need such a long beak and it evolved to have a shorter more efficient beak Natural Selection and HIV Resistance o o 75 50 Percent of HIV resistant to 3T0 Homologous and Analogous Structures 0 Homologou structures or other attributes in different species that resemble each other because of common ancestry 0 Comparing similar structures 9 common ancestor o Analogou structures that are similar in function but not in structural and developmental and evolutionary origin 0 Looks similar but doesn t have the same anatomical structure or origin Humerus adius Human Cat Whale Hat 0 0 These are homologous Homologous Structures Vertebrate Embryos 0 DNA is the universal genetic material 0 All life forms use approximately the same 20 amino acids to make proteins 0 All use ATP as the primary form of cellular energy 0 All use DNA and ribosomes to make proteins Branch no in common ancestor Lungfishes iff 1 Amphibians i4 5 a E Q Mammals 6quot my gt 82 Teirapod limbs 39 q 2 Lizards m Amnion 0 and snakes m 039 0 Crocodiles cf Homulagous characteristic 9 Ostriches I G Feathers Hawks and W other birds quot39 salsa Trees vs Scala Naturae Scala Naturae 0 Ladder of nature look up Evolution not about climbing ladder of nature from lower to higher Evolution is a bush with lineages branching from one another Look at previous diagram Convergent Evolution 0 Similarity between two organisms structures or molecules due to independent evolutionary similarities rather than descent from a common ancestor Analogous features Pharyngeal pouches Post and tail Chick embryo LM Human embryo Sugar gliders and flying squirrels are similar because of lifestyle and environment but not because of a common ancestor o Convergent evolution Analogous and Homologous Structures Dragonfly bird penguin and seal forearms o Dragonfly and seal are neither homologous nor analogous 0 Bird and penguin are homologous but not analogous o Dragonfly and bird are not homologous but analogous 0 Seal and penguin are homologous and analogous Fossil Record Fossils remains of an organism that have been preserved by being buried etc 0 Not everything that gets buried is preserved which makes it hard to find fossils Show changes in organisms through time Changes in types of organisms 0 Past organisms differ from presentday organisms 0 Many species have become extinct Not only provides evidence of smallscale changes but of origin of major groups 0 Ex Cetaceans whales porpoises dolphinS share a common ancestor with deer and hippos other evenmed ungulates Hippopotamuses Wigwam tnndhocetuw Common y ancestor A OfCelaceans L 39Darudanr WW 5 Living celaceans V 70 50 40 30 20 Key I Pelvis C Tibia Milllnns of years ago Fem r I Foot 0 a Ni Mast mammals Celaceans and evenmed ungulmes i i 1 A 4 a Canis dug b Pakicetus c Sus pig 1 Odawileus deer A Chapter 23 1242012 411 00 AM r gulations Tne SmaHest Umt of Evomuon evofve dunng fnen nfenme N huf W f oopufauons that evofve sfngfe ofgamsm fseff doesn t evofve Concegt2310eneuc Vanaffon Makes Evofunon Possfofe emen gtmufaffon Mufaffon e cnanges m nudeoude sequences of DNA ource of new aee5 and genes Pom Mufaffon rchange m one nudeoude oase m a gene gt can effnef affect of not affect the gene cnfomosomaf Mufaffon e defefe d SrupL of rearrange many OG on a cnfomosome eene Dughcatesrduphcauon of Whob segments of a cnfomosome gt can mcreasethe sfze of a genom Mufaffon rate averages f m every 100000 genes oef genefanon o CoHecwefy m a popmatfon mufaffons afefafny common Sexua Recombmauon exuaHy reproducmg ofgamsms 5exua fecomofnanon produces most of the vanaomfy m eacn genefano CrOSSmg wer durmg ofoonasef swam Pavrmgm nummngnus cnrnmosnmns r f awn mm D D testwhethera pdpmattdh ts evmvthg Descrtbes huvv genes are bemg passed thrddgh a generatmn F39Dpu attunr a gruup dr mdtvtdua s drthe sarhe Sparta hvtng m a eertath dehhed area Hard Wetnberg Egdthhhdrh d Descnbes a pdpdtatmh that ts LOIEVEIMHQ t e r the auete frequErvaS ddh t ehahge d Ftve assumptmhs N u mutatmhs are uncumng m the puputatmh There ts a targe pdpdtattdh StZE are 5 ND natura SE EEUDH There he dehe uvvr rhtgrattdh There ts rahddrh rhathg o Allele and Genotype Frequencies o Allele frequencies p9 frequency of allele 1 q9 frequency of allele 2 pq 1 Alleles are different variations of the same gene 0 Genotype Frequencies p29 frequency of homozygous dominant q29 frequency of homozygous recessive 2pq 9 frequency of heterozygotes p2 2pq q2 1 HW Equation Genotype is the 2 alleles that code for a gene aw Cquoti08 f 20c iqn2 Q 64 Ml 15v owl CALN quotCu guitarisin 4mm My 27 NC 54 MCquot 32 at H Juan 4 a quot 1 V Game es ol lhls QeHErauun 54 c 7 15 c 50 c 08 y 1 c 16c 20 a Jq Genotypes in me mm generation 54 MC am dc and 11 c c plans I Look at all the parents in a population and look at their alleles Population Genetics and Human Health 0 HW Equation can be used to estimate the percentage of the human population carrying the allele for an inherited disease 0 PKU is a recessive genetic disorder Frequency of homozygotes with this disorder is q2 0001 What is the frequency of the dominant and recessive alleles I0 q Answer 01 or1 n Solve for q and plug into equation a Sqrt of 0001 is 01 What is the frequency of people who don t have PKU heterozygotes Answer 00198 n Take the sqrt of 0001 get 01 subtract it from 1 and get 99 q n Then Take 2pq 29901 0198 lfa population has the following genotype frequency AA42 Aa46 and aa12 what are the allele frequencies Answer a Sqrt of pquot2 65 n pq1916535 n The allele frequencies are 65 and 35 lfthe frequency ofthe recessive allele is 30 the frequency of the heterozygous carriers would be Answer 42 n q30 so p70 n 2pq 23070 42 or 42 Concept 233 Natural Selection genetic drift and gene ow can alter allele frequencies in a population Genetic Drift Statistically the smaller a sample the greater the chance of deviation from a predicted result 0 It s not uncommon to have this deviation With small population sizes allele frequencies can fluctuate unpredictany from one generation to the next 0 Tends to reduce genetic variation m r 39439 r 2 x n W V W r M MU m cw m an t t 3 9e 9 mo W m r m m 3 f39 0 u m w Genetic Drift can happen in a few ways Founder effect population in which a small group goes off and forms a new population elsewhere Population bottleneck large population and for some reason it decreases dramatically o The leftovers must repopulate o Chance events some of the population can die and leave only one allele Bottleneck effect and reduction of genetic variation 039 Dr nal Eanlenecking Surviving population event population Gene Flow 0 Genetic additions to or subtractions from a population resulting from the movement of fertile individuals or gametes 0 Migration among populations 0 Tends to reduce variation among populations over time 0 Migration high little genetic variation between populations More similarities in the populations Pop 1 u9 pop 2 0 Migration low more genetic variation between populations Less similarities Pop 1 ltgt pop 2 Concept 234 Natural Selection is the only mechanism that consistently causes adaptive evolution 0 Natural selection differential success in the reproduction of different phenotypes resulting from their interactions with the environment 0 Some individuals have traits that allowthem to adapt to their environment and they typically produce more offspring contributing more to the gene pool Evolutionary Fitness Fitness the contribution an individual makes to the gene pool of the next generation relative to the contribution Tom Dick Harry Size 6 3 200 lbs 510 185 lbs 55 125 lbs Kids 2 3 5 Comments Don Juan lady s Athlete Nerd man 0 Out of the three men who has the greatest fitness Harry because he contributed most to the gene pool of the next generation But are the offspring healthy and fertile Important to keep this in mind Directional Disruptive and Stabilizing Selection forlglnal populanon Flzquency al Individuals if I L quot 39 Phenotypes lur calor Original Evolved I ll I u pupua on po ua an v 1 o A shift toward darker colored coats o B individuals in the middle are at a disadvantage 0 Increase in the individuals at the extremes o C the average ones have a advantage over the extremes o Decreases the really light and really dark furred mice Sexual Selection 0 Type of selection that favors a trait giving an individual a competitive edge in attracting or keeping a mate 0 Can result in sexual dimorphism 0 Differences in males and females such as antlers horns manes etc 0 Two Types of Sexual Selection 0 lntrasexual selection direct competition among individuals of one sex for mates of the opposite sex Males are competing forthe females lntersexual selection individuals of one sex usually females are choosy in selecting their mates from individuals ofthe other sex Fig 2315 0 The Preservation of Genetic Variation 0 Diploidy maintains genetic variation in the form of hidden recessive alleles o Balancing selectio occurs when natural selection maintains stable frequencies of two or more phenotype forms in a population 0 Traits can be advantageous or disadvantageous under specific conditions 9 because of this we tend to keep alternate alleles Heterozygote Advantage Frequency dependent selection 0 O Heterozygous advantage 0 Some individuals who are heterozygous at a particular locus have a greater fitness than homozygotes Sicklecell anemia causes mutations in hemoglobin but also confers malaria resistance 0 Fig 2317 Chapter 24 1242012 41100 AM The Origin of Species Concept 241 The biological species concept emphasizes reproductive isolation 0 Species is Latin for kind or appearance 0 Species used to be described by what they looked like but that didn t always work Grasshoppers and dogs example a They may look similar but it doesn t mean they are The Biological Species Concept 0 Defines a species as a population or group of populations whose members have the potential to interbreed in nature and produce viable fertile offspring 0 Can t be applied to Asexual organisms Fossils Organisms about which little is known regarding their reproduction Speciation fig 2414 Isolated population diverges I Gene flow r Earner ta Population gene flow five individuals 0 Dependent on Reproductive isolation Genetic divergence Reproductive isolation the existence of biological factors that impede numbers of species from producing viable fertile offspring o Prezygotic barrie preventing fertilization o Postzygotic barrie egg has been fertilized and there s a barrier that prevents the zygote from developing into a viable fertile offspring o Zygote fertilized egg Prezygotic Barrier o Impede mating between species or hinders the fertilization of ova if members of different species attempt to mate 7 r r are r W V r r r Pvezygalicbarrlers 777 7777777777 777 HIhllaK Isolallon Temporal ISDIBIIOII BEhEVIDIII lsnllllon Mechanical Isolation 0 lndxvilguals arngygnr G S S G snecres o f f 9 Q A the species prefer different habitats B reproductive periods occur at different times C there are certain behaviors that lead to mating and if the behaviors are incompatible they won t mate D reproductive structures are incompatible E receptor proteins on surface of sperm and egg must match Postzygotic Barrier Often prevents the hybrid zygote from developing into a viable fertile adult Wayne haniuu Pwmygwc bani Manna xymm vIuimy Manna nymm Farmin mun lmnk nwn Gumm Isnllllon WW c l the offspring doesn t develop into an adult 2 mules are sterile they live but they can t reproduce o chromosomes incompatible enough to not allow meiosis in offspring 3 Closely related species will have viable first generation offspring but all subsequent offspring will be weak and won t complete development because of deleterious chromosomes Limitations of the BSC lt Grizzly hear u mm v Pular bearw mlrmmus A f hrlniln rnlarmarquot o The two species of bears diverged over the last thousand years or so and recently came back together and produced the grolar bear a hybrid of the two Clicker question o Is gametic isolation a prezygotic or postaygotic isolating mechanism 0 Prezygotic The egg and sperm can come together but there is no fertilization Concept 242 Speciation can take place with or without geographic separation Speciation can occur in two ways 0 Allopatric speciation geographic barrier o Sympatric speciation other reproductive isolating mechanisms Allopatric Speciation o Other country 0 Gene flow is stopped or reduced when a population is divided into two or more geographically isolated subpopulations Eeogr uphic burrlei Iso ates populations Generic drifT muTaTion natural 55 echon Cause gznztic divcrgoncz Barrier removed populations quotIIX but interbreed IL armasus Mimic Ocean Isthmus o1 Fulani Paclllc own A Danamensls k mlllsae Establishing Reproductive Isolation li39il39m rii l lnilial population Some mes Some flies raised on raised an maiiuse medium starch medium Mating experiments aner 40 generaiions male Femal sumquot swab Starch Malmse pouulu unl pouulzllu z E g 2 22 I 9 5 g 15 15 2 5 o 3 n r 2 3 s g g e 20 3 12 15 m 1 g s E a 8 Maling quotequencins Mating lrequencies In experimental group In conimi group o 0 Fruit flies divided into two habitats 0 Starch vs maltose 0 Isolated for a year and brought back together to mate but there wasn t a lot of mating between the two groups Sympatric Speciation 0 Same country c Speciation that takes place in geographically overlapping populations Single species h mngnznus innni Emirmmmml mm MD habitats pnpulmmna isnlmed by nun Emmmmai przssire m adapt gcnziic divugcnoe Sufficizni isaiaium Polyploidv 0 Presence of extra sets of chromosomes in cells due to accidents during meiosis or mitosis Has caused sympatric speciation in many plant species but not many animals Autoploidv individual has more than two chromosome sets all derived from a single species Alloploidv species with multiple sets of chromosomes derived from different species 7 ell gt f l divisionf lt I error f d 2n 6 Tetraploid cell 12 2quot y A f 1 a gs 8535 2quot New species Gametes produced b plaids O l 0 One mechanism for allopolyploidy SDEClPS 5 Unveduced 2quot gimme umgzcea f ltziom 5w ll 1n chmmnsums NDMOWMES emu 4 a q S W I Normal Viable lenlle 9 make Normal hybrid Species A n 3 gamete allapnlyuluml 2n 6 II 2 2n ID Sympatric Speciation in Progress 0 The apple maggot fly 0 Laid eggs in Hawthorne tree until apple tree was introduced and now it uses both 0 There is a difference in the season for ripening fruit between the trees so the flies don t hatch at the same time Spccia l39ion a ln cichlid fish Sympatric speciation has resulted from random mating due to sexual selection Monochromatic Normal light mange light i FV39 lt p pundamilia Clicker question a What is the first step in allopatric speciation 390 Geographic isolation Clicker Question 0 All but are likely to promote sympatric speciation 0 Gene flow because a lot of gene flow means no speciation Concth 243 Hybrid Zones Provide Opportunities to Study Factors that Cause Reproductive Isolation Possible outcomes for hybrids Isoraiw pnpulanon diverges Possible 39 ourccmns V nymm 4 m g Reinforceman an Fuslnn Hyhrm an Earrievlo Population gene Haw we in 39 iduals Subilliy are h reinforcement a lot of genetic divergence o Hybrids at a lower fitness level become less common 0 The two species are incapable of hybridization Fusion two populations come together to produce hybrid offspring and this reestablishes gene flow and makes a single species Stability the two species come together to make hybrids that can survive and maintain a steady population 0 Example of Stability mamm haw mum ms csum in an an m w n m an lulu an Pumime slslIA amuvum uniu Aslimpomn mn39 Hummus murmurs kin WIIIW mn39 Produce hybrids in a narrow hybrid zone and the hybrids are less viable than the parent species but they stay stable over many years The Breakdown of Reproductive Barriers Fusion Pundamilia pundamilia Pundamilia quotturbid water hybrid offspring lrom a location r o The females will only breed with males of the correct color but if they can t see the colors they will breed with either species Chapter 25 1242012 41100 AM The History of Life on Earth Early Earth 0 Earth is about 46 billion years BY old 0 Radiometric dating of meteorites and moon rocks 0 Life arose about 38 BY ago 0 Chemical traces in rocks 38 BY 0 Fossil bacteria in rocks 35 BY 0 No spontaneous generation now but must might have happened then 0 Conditions were good for spontaneous creation of organisms 0 Atmosphere neutralizing atmosphere instead of the harsh one we have today 0 Formation of organic molecules was easy 0 002 0H4 NH3 H28 and H20 0 Abundant energy to drive reactions 0 Frequent storms with much lightening Frequent volcanic eruptions Frequent meteor impacts UV light from the sun 0 O O Testable Hypotheses explaining the origin of life 0 Abiotic synthesis of small organic molecules 0 Joining these molecules together into polymers 0 Packaging these molecules into probionts o The origin of selfreplicating molecules Miller amp Urey Experiments 39 Water vapnr u i AXCondeuisar fill couled waler canlaining Sample for chemical analysis 0 liquid wasrclroudy with brownish color they found amino acids Alternative Hypotheses 0 First organic compounds may have been synthesized near hydrothermal vents o Extraterrestrial origins Abiotic Synthesis of Polymers 0 Small organic molecules polymerize when they are concentrated on hot sand or clay Probionts o Aggregates of abiotically produced molecules surrounded by a membrane 0 Liposomes can form When lipids or other organic molecules are added to water llbuzolll s a m Manama W WFDDEW a ziwmilibqucunu p quotsnags r J Fquot 5 ENEquot L lavah lt quot lemmwym 39 V o eincoaobpoabum a Pranurior molecula plus munlmorillonlla clay 5 m chnnar molecules onty nuaqu Iurbldlty an Index or veslcle number 2b 4a TimE minmes a SelfInembly l 20 mu 1 Reproduminn c Absorption a RNA The Chicken or the Egg 0 Now DNA RNA9Protein 0 Need proteins to synthesize more DNA I Then earliest cells used RNA to store info 0 Ribosomes to catalyze reactions Possible Seguence of Events Leading to First Prokaryotes o Selfreplicating system enclosed in a selectively permeable protective lipid sphere Clicker Question on test Oxygen has a influence on the formation of complex organic molecules because 0 Negative it is highly reactive Concept 252 The Fossil Record Documents the History of Life Sedimentary strata reveal the relative ages of fossils o Fossils near surface are more recent 0 Deeper fossils are more ancient Fossil records show great changes in organisms through time P4 n v ilnumllwumulvlmr mam 0 Dating of Fos I Order of fossils in rock strata tells us the unique sequence in which they were Iain down 0 This provides relative ages not absolute dates 0 Table 251 Radiometric Dating 0 Can determine absolute ages of fossils O Radioactive isotopes decay into a daughter isotope at a fixed constant rate 0 12 life amount of time it takes for 50 of an isotope to decay Fraclinn cl parent lsampa remaining 2 l1mellallllves Clicker Q c When a certain rock formed it contained 12 mgquot40K the rock now contains 3 mgquot40L The halflife of 1 40K is 13 billion ears How old is the rock 0 26 BY o 12 life 0 1 2 3 0 40K mg 12 6 3 15 0 Two half lives 13x2 26 by I Carbon14 decays into Nitrogen14 and has a 12 life of 5730 years If you find a fossil with exactly equal amounts of C14 and N14 when did that organism die 5730 years ago 1z 0 1 2 3 100 50 25 125 5730 x 1 5730 0000 Concept 253 Key events in life s history include the origins of singlecelled and multicelled organisms and the colonization of land What were the earliest organisms like I First organisms were prokaryotes o Bacteria and Archaea o Fed on accumulated organic molecules heterotrophic Some were likely autotrophic I Oxygenic photosynthetic bacteria evolved between 35 and 27 BY ago I C02 H20 9 food 02 I Oxygen begins accumulating in the atmosphere v r v o 2 I Clicker Question 0 Which is the correct sequence of events Anaerobic cells gt photosynthesis gt 02 gt aerobic metabolism The First Eukaryotes I The oldest fossils of eukaryotic cells are 21 by old I Endosymbiotic Theory o Mitochondria and plastids were formerly small prokaryotes living within larger host cells 0 Were possibly undigested prey or internal parasites or mutualists cytoplasm Plasma membrane 39 b Ancestral rokaryote Endoplasmicreliculum Nucleus Nuclear envelope n Aeroblc heterotrophic Photosynthetic prukaryole prokaryole Mitochondrion Mitochondrlon An Eeslral helerotrophic 739 Flaslid Ancestral photosynthetic eukaryote O u r r o Clicker Q What evidence suggests that eukaryotic cells formed symbiotic relationships with bacteria Both chloroplasts and mitochondria contain DNA that is distinct from that found in the nucleus of the eukaryotic a cell Similarities in inner membrane structure and functions Both chloroplasts and mitochondria have their own ribosomes and make proteins independent from the cell a u am gt mwl u mu m mm mm pmmmm WhamIn cmcmnaxugy Shuwsume sca esmvuwed mme ms1urv mm un Eanh W a N EXAM l Chapters 2225 82311 Chapter 22 Descent with Modification A Darwinian View of Life What is Evolution amp Adaption 0 Evolution 2 main ideas I Change over time of the genetic composition ofa population I Descent of modern organisms with modification from preexisting organisms I We extract way far enough which life began on earth that we have a common descendants ofancestors diversity of life Gene frequencies Evolutiona adaptation o Accumulation of inherited characteristics that enhances organism s ability to survive specific environments PreDarwinism Theory of Evolution 0 JeanLafitte Lamarck o Inheritance ofacquired characteristics I Bodies of living organisms are modified through the use or disuse of parts I These modifications are inherited by offspring I Giraffes ancestors were much shorter modern giraffes have longer legs and longer necks because of the long lifetime of stretching I This idea turned out to be wrong because we know a lot about genes Evolution by Natural Selection 0 Darwin amp Wallace developed the theory independently 0 Darwin voyage of the Beagle right out of college amp changed the world Collect rocks amp things along the way Over time he made a lot of observations Species don t fit they change over time share a common ancestor Worked out a mechanism to see how changes occur 0 Wallace naturalist in Indonesia collected birds and saw many mosquitoes a lot of malaria Natural selection and passed it on to Darwin to check Natural Selection 0 The unequal survival and reproduction of organisms due to environmental forces resulting in the preservation of favorable adaptations 0 Process quotselectsquot from what is available in the gene pool 0 New characteristics are NOT created on demand I Traits LESS favorable are NOT likely to be passed over time Mechanism Behind Natural Selection pg 458 0 Potential for rapid reproductionRelatively constant resources and population size over time 9Competition for survival and reproductionVariability in structure 9Natural Selection On the average the fittest organisms leave the most offspring9Evolution The genetic makeup of the population changes over time driven by natural selection Changing environment may have traits to move on those that survive and reproduce will have the more impact on the genes Unequal survival bc they have traits and passes on their genes to individuals a o Selective breeding of organisms to encourage the occurrence ofdesirable traits o Analogous to natural selection 0 Livestock animals crops Takes offspring that posses certain traits and breed I Ex wild mustard 9 terminal bud Brussels sprouts broccoli cauliflower 223 Evolution is supported by an overwhelming amount of scientific evidence Examples of Natural selection figure 2213 0 Experimental transplant of guppies Q Within a few weeks of treatment with the drug 3TC a patient s HIV population consists almost entirely of 3TCresistant viruses How can this best be explained A a few drug resistant viruses were present at the start of treatment and natural selection 0 Single drug therapy one drug to treat decrease viral load over time virus start to resist I l start with different variants of HIV particles I 2 single drug reduces fitness of most variants I 3 resistant variants proliferate grow Fossil record 0 Show change in organisms through time 0 Change in types of organisms I Past organisms differ from presentday organisms I Many species have become extinct 0 Fossil record not only provides evidence of smallscale changes but of origin of major groups I Ex the cetaceans Common ancestral Homologous amp Analogous Structures 0 Homologous I Structures or other attributes in different species that resemble each other because of common ancestry o Analogous I Structures that are similar in function but NOT in structure and developmental and evolutionary origin 0 Homologous Structures Mammalian Forelimbs Ex human cat whale bat I All have the same underline anatomy humorous radius ulna phalanges I Use forearm for different purposes swim fly Have same gene to determine their development Go on slightly different paths 0 Homologous Structures Vertebrate Embryos I All vertebrates share similar developmental genes I Differences arise by some genes being switched on or off at varying times during development I Ex pharyngeal pouches postanal tail 0 Chick embryo human embryo o Homologous Structures Biochemistry and Molecular Biology I DNA is universal genetic material I All life forms use approximately the same 20 amino acids to make proteins All uses ATP as the primary form of cellular energy All use RNA and ribosome to make protein All living things originated from common ancestors It worked well enough for the ancestors to survive and evolve o Homologies and quotTree Thinkingquot Trees vs ScalaNaturae o ScalaNaturae I Ladder of nature see pg 453 0 Evolution is NOT about climbing quotladder of nature from lower to higher 0 Evolution is a quotbushquot with lineages branching from one another Biogeograghy 0 Geographic distribution of species I Closely related species tend to be found in the same region 0 Convergent evolution I Similarity between 2 organisms structures or molecules due to independent evolution along similar lines rather than descent from a common ancestor 0 Ex similar structures not common in ancestry I Sugar glider from Australia are marsupials I No skin flaps I Flying squirrel from North America are placental mammals I Flaps of skin Function is analogous but the underlining structure is homologous Endemic found nowhere else in the world Q Which of the following pairs of structures is least to represent homology a The wings ofa bat and the forelimbs of a human b The hemoglobin of a baboon and that ofa gorilla c The legs of a bird and those of an insect d The mitochondria of a plant and those of an animal A C the legs of a bird and those of an insect Chapter 23 The Evolution of Populations The smallest unit of evolution 0 One common misconception about evolution is that individual organisms evolve during their lifetime 0 Evolutionary processes eg natural selection acts on individuals but populations evolve Populations A group of individuals of the same species living in a certain defined area 0 No mingling in the 2 different populations 231 Mutation and sexual recombination produce the genetic variation that makes evolution possible Mutation o Mutation changes in nucleotide sequence of DNA I Source of new alleles and genes I Although it is NOT a cause of evolutionary change because it is random A mutation could turn out to be a disadvantage Point mutation change in one nucleotide base in a gene Chromosomal mutations delete disrupt or rearrange many loci on a chromosome Gene duplications duplication of whole segments of a chromosome Mutation rate averages l in every 100000 genes per generation Sexual reproduction o In sexually reproducing organisms sexual recombination produces most of the variability in each generation I Crossing over during prophasel I Shuffling genes recombination 2 homologous chromosomes with 2 diff alleles on that chromosome I Independent assortment during metaphase I Human have 23 pairs of homologous chromosomes and genes can be mixed up somehow OOOO Variation within a population 0 Discrete characters classified on an eitheror basis I Eg flower color in pea plants purple or white 0 Quantitative characters vary along a continuum within a population I Eg height weight short or tall skinny or fat I Determined by genes and environmental habits milk 83011 232 The HardyWeinberg equation can be used to test whether a population is evolving Population group of individuals of the same species living in a certain defined area HardyWeinbergEquilibrium o HW equilibrium describes a population that is not evolving ie allele frequencies don t change 0 Five assumptions behind HW equilibrium No mutations 2 Random mating 3 No natural selections individual has an equal chance of surviving amp reproducing 4 Large population size smaller the population more likely allele frequencies will fluctuate genetic drift 5 No gene flow transfer of alleles between populations Allele amp Genotype Frequencies o HW equation 39 pz2pqqz l o Allele frequencies I p frequency ofallele 1 I q frequency ofallele 2 I p q 1 o Genotype frequencies p frequency of homozygous dominant I q2 frequency of homozygous recessive I 2pq frequency of heterozygous o HW Equilibrium Figure 237 I Gametes for each generation are drawn at random from the gene pool of the previous generation Population Genetics amp Human Health 0 HW equation can be used to estimate of the human population carrying the allele for an inherited disease 0 PKU is a recessive genetic disorder I Frequency of homozygote with this disorder is qZ 00001 I What is the frequency of the dominant recessive alleles p q I p 099 p 1 001 I q 001 q sqrt00001 Q The frequency of carriers heterozygous people who do not have PKU is A 00198 2pq 2 099 001 Q If a population has the following genotype frequencies AA 042 Aa 046 aa 012 what are the allele frequencies AA 065 a 035 p2 042 p sqrt042 065 2pq 046 q2 012 pq1 q35 Q If the frequency of the recessive allele is 30 then the frequency of the heterozygous carriers would be A 42 q 030 p 1 030 070 2pq 20307 042 given q find p then plug in for 2pq equation 233 Natural selection genetic drift and gene flow can alter allele frequencies in a population Genetic Drift completely chance 0 Statistically the smaller a sample the greater the chance ofdeviation from a predicted result 0 With small population sizes allele frequencies can fluctuate unpredictably from one generation to the next I Genes that are lost makes population more fit 0 Tends to reduce genetic variation 0 Figure 239 Genetic drift 0 Founder effect when a few individuals get separated from a population their new population s gene pool differs I Frequency of red allele is low in original population I Several of the travelers happen to carry the red allele I Frequency of red allele much higher in new population 0 Population bottleneck I Frequency of red allele is low in original population Many survivors of tidal wave happen to carry red allele 0 Chance event I Frequency of red allele is low in the original population I The only person with red allele dies I No more red allele 0 Effects of Genetic Drift 1 Genetic Drift is significant in small populations 2 Genetic drift can cause allele frequencies to change at random 3 Genetic drift can lead to a loss of genetic variation in a population 4 Genetic drift can cause harmful alleles to become fixed Bottleneck Effectamp Reduction of genetic variation Gene flow Genetic additions to or substitutions from a population resulting from the movement of fertile individuals or gametes Migration among populations Tends to reduce variation among populations over time Migration high little genetic variation between populations Migration low more genetic variation between populations O 0000 234 Natural selection is the only mechanism that consistently causes adaptive evolution Natural selection differential success In the reproduction of different phenotypes resulting from their interactions with the environment Evolutionary Fitness 0 Fitness the contribution an individual makes to the gene pool of the next generation relative to the contributions of other individuals Directional Disruptive amp Stabilizing Selection Fig 2313 0 Directional when conditions favor individuals exhibiting one extreme of a phenotypic range thereby shifting a population s frequency curve for the phenotypic character in one direction or the other 0 Disruptive when conditions favor individuals at both extremes ofa phenotypic range over individuals with intermediate phenotypes Stabilizing acts against both extreme phenotypes and favors intermediate variants O Q A population of seed cracker finches has small and largebilled birds specializing in soft and hard seeds respectively If climatic change resulted in a loss of the softseeded plants what type of selection would then operate on the finch population a Disruptive b Directional c Stabilizing d Sexual A b Directional Sexual selection 0 Type of selection that favors a trait giving an individual a competitive edge in attracting or keeping a mate I Male lions have mane female doesn tmae rams have bigger horns female doesn t 0 Can result in sexual dimorphismpeacocks have bright showy feathers peahens do not 0 lntrasexual selection direct competition among individuals of one sex for mates of the opposite sex I Has to do with mate choice Direct competition Winner male can get access to female And loser doesn t 9111 Q Immigration of individuals into a population in HW equilibrium will not upset the equilibrium if 1 They are beyond the age of reproduction 2 Females amp males are in equal proportion 3 They mate randomly in the new population 4 They arrive in large numbers A 1 they are beyond the age of reproduction This has to do with gene flow Reproductive age has an impact because the older they are they won39t mate 0 lntersexual selection individuals of one sex usually females are choosy in selecting their mates from individuals of the other sex aka mate choice I g peacocks have bright fluorescent color feathers peahens don t have large color display of feathers Females are attracted by the display of good genes to pass on to the offspring Check him out The Preservation of Genetic Variation 0 Diploidy maintains genetic variation in the form of hidden recessive alleles I 2 copies of each homologous chromosome one alleles dominant one allele recessive o Balancing selection occurs when natural selection maintains stable frequencies of two or more phenotypic forms in a population trade offs between different alleles That allele might cause to be less fit Sustain frequencies I Heterozygote advantage defined in terms of genotype not phenotype I Frequency dependent selection the fitness of a phenotype depends on how common it is in the population one phenotype more common alternate form becomes less common Then the 2 alleles balance Heterozygote advantage 0 Some individuals who are heterozygous at a particular locus have a greater fitness than homozygotes o Sicklecell allele causes mutations in hemoglobin also confers malaria resistance I Hard time making through capillaries and will burst open making it lethal Chapter 24 The Origin of Species 241 The biological species concept emphasizes reproductiveisolation Species Latin for quotkindquot or quotappearancequot The Biological Species concept 0 Defines a species as a population or group of populations whose members have the potential to interbreed in nature and produce viable fertile o spring 0 Cannot be applied to I Asexual organisms I Fossils I Organisms about which little is known regarding their reproduction I If two species mate at different times of the year they are NOT the same species Speciation the process by which one species splits into 2 or more species Figure 2414 0 Dependent on I Reproductive isolation I Genetic divergence Establishing reproductive Isolation 0 Fruit flies mating are the same from one group to the next Similar genetic changes maintain their ability to mate Reproductive isolation fig 243 o The existence of biological factors that impede members of two species from producing viable fertile offspring o Prezygotic barriers I Prevent sperm from fertilizing egg I Impede mating between species or hinder the fertilization of ova if members of different species attempt to mate 0 Postzygotic barriers I Zygote has been formed the 2 parents involved aren t compatible and offspring is not capable to grow I Impede mating between species or hinder the fertilization of ova if members of different species attempt to mate gt In time they will die out o Zygote fertilized egg Prezygotic barriers I Habitat isolation I Temporal isolation species that breed at different times I Behavioral isolation different courtship rituals I Mechanical isolation mating is attempted but unsuccessful I Gametic isolation sperm can t fertilize egg 0 Postzygotic barriers I Reduced hybrid viability hybrid doesn t survive or it is difficult for it to survive I Reduced hybrid fertility hybrid can t reproduce mule I Hybrid breakdown the hybrid soffspring are sterile or weak 0 Q Two species of pine are found in the same habitat but release pollen at different times during the year This is an example of isolation A temporal fertilizing is happening in a time of year for one species and another time for another species Q Is gametic isolation a prezygotic or postzygotic isolating mechanism A Prezygotic eggs and sperm cant get together because they don t match up 242 Speciation can take place with or without geographic separation Speciation can occur in 2 ways Figure 245 o Allopatric speciation o Sympatric speciation 0 Once they are reproductively isolated then speciation can occur Allopatric speciation 0 Means quotother country 0 Gene flow is interrupted or reduced when a population is divided into 2 or more geographically isolated subpopulations I Ex species of frogs 2 different locations of frogs are more closely related to each other than the 2 frogs that are located in the same areas I Ex Hawaiian silversword related to westcoast Bc the 2 are separated by the pacific ocean gene flow between them is limited amp they become more and more different and become a new species I Also shrimps and crabs are different bc of geographic barrier Sympatric quotsame country speciation o Speciation that takes place in geographically overlapping populations I Separated by different habitats over a period of time Natural selections occur genetic divergence Which creates 2 new species I Polyploidy habitat differentiation and sexual selection can also promote allopatric speciation Pomploidv o The presence of extra sets of chromosomes in cells due to accidents during meiosis 0 Has caused sympatric speciation in many plant species 0 lSt form I Autopolyploidv individual has more than two chromosome sets all derived from a single species 0 Rare occurrence in animals but occurs often in plants I Ex strawberries 8 sets of chromosomes 0 2quotd form I Allopolyploid1quotallo means different species with multiple sets of chromosomes derived from different species 9611 Q Which of the following is the first step in the process of allopatric speciation 1 Genetic drift Interspecies contact Geographic isolation Reproductive isolation PWN A 3 Geographic isolation gene flow genetic divergence Q Plant speciesA has a diploid number of 12 Plant species B has a diploid number of 16 A new species C arises as an allopolyploid from A and B the likely diploid number of species C would be A 28 Allopolyploidy A 12 B 16 add 1216 C 28 Autopolyploid A 12 multiply by 2 12x2 24 B 24 Sympatric Speciation in Progress In cichlid fish 0 Sympatric speciation has resulted from nonrandom mating due to sexual selection I Based on coloration patterns females choose which color to mate with but put all of them under orange light the females do not discriminate and will mate with either 243 Hybrid Zones Provide Opportunities to Study Factors that Cause Reproductive Isolation Possible outcomes for hybrids o Reinforcementof barriers no more hybrids 0 Fusion of species 0 Stability I 2 species of toad that occur in Eastern Europe Where they meet in the middle and produce viable offspring in the hybrid zone Not enough gene flow between individuals from either side The breakdown of reproductive barriers fusion 0 Water was clear and Colorations were distinct and obvious between the 2 species Over the years the lighting conditions aren t favorable and a lot of hybrid offspring from a location with turbid water So much cross breeding between them Q All but which of the following are likely to promote sympatric speciation 1 Gene flow discourage speciation allopatric or sympatric 2 Ecological isolation species in same area but occupy different habitat water or land 3 Temporal isolation might occupy same area produce different time of year 4 Polyploidy doubling of chromosomes number hybridization event species from one generation A 1 Gene flow 9 Which of the following is not considered a requirement for speciation to occur 1 Populations must be isolated geographically or in some other manner from one another 2 Isolated populations must become genetically distinct from one another 3 Exchanges of genetic information must be restricted between populations 4 High levels of gene flow among population must occur A 4 High levels of gene flow among population must occur Q The origin of a new plant species by hybridization coupled with accidents during nuclear division is an example of A allopolyploidy hybridization means mating with similar species Chapter 25 The History of Life on Earth Early Earth 0 Earth is about 46 billion years BY old I Radiometric dating of meteorites amp moon rocks 0 Life arose about 38 BY ago I Chemical traces in rocks 38 BY ago I Fossil bacteria in rocks 35 BY ago 0 No spontaneous generation now but must have happened then some point in time Conditions on Early Earth 0 Atmosphere I COZ CH2 NHZ HZSHZO called reduced compound fairly reactive I No free oxygen 0 Abundant energy to drive reactions I Frequent storms w much lightening I Frequent volcanic eruptions hot liquid magma provides energy I Frequent meteor impacts I UV light from the sun no oxygen in air so no ozone layer so plenty of sunlight Testable hypotheses explaining the origin of life 1 Abiotic nonliving synthesis of small organic molecules has to be produced by living things making them 2 Joining these molecules into polymers macromolecules 3 Packing these molecules into quotprotobiontsquot protocells 4 The origin of selfreplicating molecules DNA can store information and can replicate itself to be passed on from one generation to another Miller amp Urey Experiments Figure 42 0 1950s conducted experiment Set apparatus whole thing is sealed off by vacuum Water vapor was produced by boiling water methane and other gas They set it up and let go for a couple ofdays they started off with clear liquid then cloudy then brown They found organic materials They demonstrated that they don t need a living thing to produce organic compounds 0 Substances in Miller Urey experiment hydrogen water methane ammonia Alternative hypotheses Figure 252 1 First organic compounds may have been synthesized near hydrothermal vents volcanoes 2 Extraterrestrial origin organic compounds that are trapped in things like meteorites can be incorporated into living organisms Abiotic synthesis of polymers 0 Small organic molecules polymerize when they are concentrated on hot sand clay or rock Protobionts Figure 253 o Aggregates of abiotically produced molecules surrounded by a membrane 0 Liposomes can form when lipids or other organic molecules are added to water The chicken or the egg 0 Now DNA 9 RNA 9 Protein I Need proteins to synthesize more DNA 0 Then I Earliest cells used RNA to store info I Ribozymes to catalyze reactions Ribozymes 0 Found to catalyze many different reactions including I Self splicing I Making complementary copies of shortstretches of RNA 9811 Q Oxygen has a influence on the formation of complex organic molecules because A NEGATIVE it is highly reactive Q Which of the following statement does NOT support the hypothesis of an RNA world Singlestranded RNA can assume many 3D shapes specified by their nucleotide sequence Some RNAs are important catalysts inmodern cells ribosome The oldest known fossils contain traces of RNA physical remains cant reveal RNA RNA can store genetic information PWN A 3 The oldest known fossils contain traces of RNA physical remains can t reveal RNA Possible Sequence Leading to First Prokaryotes o selfreplicating system enclosed in a selective permeable protective sphere 0 DNA 9 RNA 9 enzymes and other proteins 0 quotformation of proteinsRNA systems evolution of DNA quotformation of lipid sphere o Spontaneous formation of lipids carbohydrates amino acids proteins nucleotides under abiotic conditions 252 The fossil record documents the history of life Fossil Documents the History of Life 0 Sedimentary strata rock layers reveal the relative ages of fossils I Fossils near surface more recent I Deeper fossils more ancient 0 Fossil records shows great changes in organisms through time Dating of Fossils 0 Order of fossils in rock strata tells us the sequence in which they were laid down 0 This provides relative ages not absolute dates Radiometric Dating 0 Can determine absolute ages of fossils I Radioactive isotopes decay into a daughter isotope at a fixed rate I m amount of time it takes for 50 ofan isotope to decay Q When a certain rock formed it contained 12 mg 40K The rock now contains 3 mg 40K The halflife of 40K is 13 billion years How old is the rock 3 Q into Nitrogen14 N14 when did that organism die 5730 years amounts C14 Percent 253 Key events in life s history include the origins of singlecelled and multicelled organisms and the colonization of land What were the earliest organisms like 0 First organisms were prokaryotes I Bacteria amparchea I Fed on accumulated organism molecules heterotrophic some were like autotrophic use sunlight for photosynthesis or carbon dioxide as a form of carbon Oxygenic photosynthetic bacteria evolved between 35 amp 27 BYA 0 CO2 HZO 9Food 02 Oxygen begins accumulating in the atmosphere 27 BYA Q Which is the correct sequence of events A Anaerobic cells gt photosynthesis gt 02 by product gt aerobic metabolism The First Eukaryotes o Oldest fossils cells are 21 BY old 0 Endosymbiotic Theory I Mitochondria amp plastids were formerly small prokaryotes living within larger host cells I Were possibly undigested prey or internal parasites or mutualists Q What evidence suggests that eukaryotic cells formed symbiotic relationships with bacteria 1 Both chloroplasts and mitochondria contain DNA that is distinct from that found in the nucleus of the eukaryotic cell 2 Similarities in inner membranes structure and functions 3 Both chloroplasts and mitochondria have their own ribosomes and make proteins independent from the cell A All the above Clock Analogy fig 257 Earth divided into 3 eons l 2 3 O 254 Archaean Proterozoic Phanerozoic Phanerozoic divided into 3 eras Paleozoic 2 Mesozoic 3 Cenozoic current Shows time scales involved in the history of life on Earth Origin of solar system amp Earth 9 Prokaryotes9Singlecelled Eukaryotes9Multicellular Eukaryotes Adaptive radiation period of evolutionary change in which groups of organisms form very many new species whose adaptations allow them to fill different ecological roles in their communities 255 Heterochrony an evolutionary change in the rate or timing of developmental events Homeotic genes determine such basic features as where a pair of wings and a pair of legs will develop on a bird or how a plant s flowers are arranged BIOLOGY 1202 o Descent with Modification a Darwinian View of Life 0 What is evolution and adaptation 0 Evolution two main ideas I 1 Change over time of the genetic composition of a population I 2 Decent of modern 0 39 with quotquot 39 from r 39 39 g organisms o Evolutionary adaptation I Accumulation of inherited characteristics that enhance organisms ability to survive in specific environments 0 PreDarwinian Theory of Evolution 0 Catastrophism I The principle that events in the past occurred suddenly by mechanisms not operating today 0 Uniformitarianism I Geologic change results from mechanisms that operated in the past in the same manner as at the present time o Gradualism I The hypothesis that evolution proceeds chiefly by the accumulation of gradual changes 0 Lamarck I Use and disuse o Bodies of living organisms are modified through the use or disuse of parts I Inheritance of acquired characteristics 0 These modifications are inherited by offspring 0 These ideas turned out to be wrong 0 Evolution by Natural Selection 0 Darwin and Wallace developed the theory independently I Darwin voyage of the Beagle I Wallace naturalist in Indonesia 0 Natural Selection 0 The unequal survival and reproduction of organisms due to environmental forces resulting in the preservation of favorable adaptations 0 Process quotselectsquot from what is available in the gene pool 0 New characteristics are not created on demand I Unfavorable traits decrease in frequency favorable traits increase 0 Mechanisms Behind Natural Selection 0 Observations I Individuals in a population vary in their heritable characteristics I Organisms produce more offspring than the environment can support 0 Inferences I Individuals that are well suited to their environment tend to leave more offspring than other individuals I Over time favorable traits accumulate in the population 0 Natural Selection A Summary 0 Natural selection is a process in which individuals that have certain heritable traits survive and reproduce at a higher rate than other individuals because of those traits 0 Over time natural selection can increase the match between organisms and their environment o If an environment changes or if individuals move to a new environment natural selection may result in adaptation to these new conditions sometimes giving rise to new species 0 Although natural selection occurs through interactions between individual organisms and their environment individuals do not evolve I It is the population that evolves over time 0 Natural selection can amplify or diminish only those heritable traits that differ among the individuals in a population I Thus even ifa trait is heritable ifall the individuals in a population are genetically identical for that trait evolution by natural selection cannot occur 0 Environmental factors vary from place to place and over time I A trait that is favorable in one place or time may be useless or even detrimental in other places or times Natural selection is always operating but which traits are favored depends on the context in which a species lives and mates 0 Artificial Selection 0 Selective breeding of organisms to encourage the occurrence of desirable traits o Analogous to natural selection 0 Evolution is supported by an overwhelming amount of scientific evidence 0 Homologous and Analogous Structures 0 Homologous I Structures or other attributes in different species that resemble each other because of common ancestry I Not similar in function 0 Example mammalian forelimbs o Analogous I Structures that are mquot and evolutionary origin 0 Homologous Structures Vertebrate Embryos o All vertebrates share similar developmental genes 0 Differences arise by some genes being switched on or off at varying times during development 0 Homologous Structures Biochemistry and Molecular Biology 0 DNA is universal genetic material 0 All life forms use approximately the same 20 amino acids to make proteins 0 All use ATP as the primary form of cellular energy 0 All use RNA and ribosomes to make proteins 0 Trees vs Scala Naturae o ScalaNaturae I Ladder of nature see pg 453 0 Evolution not about climbing llladder of nature from lower to higher 0 Evolution is a quotbushquot with lineages branching from one another 0 Convergent Evolution 0 Similarity between 2 organisms structures or molecules due to independent evolution along similar lines rather than descent from a common ancestor 0 Fossil Record 0 Show change in organisms through time 0 Change in types oforganisms I Past organisms differ from presentday organisms I Many species have become extinct 0 Not only provides evidence of smallscale changes but of origin of major groups I Eg the cetaceans o The Evolution of Populations o The smallest unit of evolution I One common misconception about evolution is that individual organisms evolve during their lifetime I Evolutionary processes eg natural selection act on individuals but populations evolve 0 Genetic variation makes evolution possible 0 Mutation o Mutations changes in nucleotide sequence of DNA I Source of new alleles and genes 0 Point mutation change in one nucleotide base in a gene 0 Chromosomal mutations delete disrupt or rearrange many loci on a chromosome 0 Gene duplications duplication of whole segments of a chromosome 0 Mutation rate averages 1 in every 100000 genes per generation 0 Sexual Recombination o nsexually r 39g 39 sexual u produces most of the variability in each generation I Crossing over during prophase I Independent assortment during metaphase 0 Variation within a population 0 Discrete characters classified on an eitheror basis I Eg flower color in pea plants
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