BISC208 Final Exam Study Guide
BISC208 Final Exam Study Guide bisc208
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This 50 page Study Guide was uploaded by Kristen Ritchie on Monday January 18, 2016. The Study Guide belongs to bisc208 at University of Delaware taught by Catherine Safran in Fall 2015. Since its upload, it has received 60 views. For similar materials see Introduction to Biology II in Biosystem Engineering at University of Delaware.
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Date Created: 01/18/16
Bio final review! 12/13/2015 ▯ Chpt. 18.2 — The fossil record ▯ •know where fossils can be found sedimentary rock-better at preservation of fossils, igneous is not as good because it is too compact, but it is good if there is a layer of igneous on top of sedimentary to protect the fossil ▯ •understand how decay of radioisotopes works radioisotopes are unstable isotopes that release electrons and decay; decay is not affected by the environment (pressure, temperature, chemical reactions) ▯ • know the difference between stable and unstable isotopes/atomic number and atomic mass because of different numbers of neutrons in the nuclei, their nuclei may be unstable, resulting in the loss of some electrons ▯ •explain how radioisotope dating works you compare the amount of C-14 to the amount of C-12 in specimens that lived in the past. Living plants take in C-12 and C- 14, dead plants no longer take in carbon, and C-14 decays over time to N-14. ▯ •know what the half-life of a radioisotope represent and how its decays overtime the half-life is the amount of time it takes for half of the sample to decay, it decays exponentially and the unstable isotope releases electrons. ▯ •know why carbon dating is used to date organic specimen and why carbon molecules end up being part of living organisms when they die carbon fixation is when autotrophs convert inorganic carbon into organic compounds, and when heterotrophs eat these compounds, the body breaks them down into macromolecules and uses them in the body, so the carbon stays in the body. ▯ •know how to calculate the approximate age of a fossil if the fraction of the radioisotope normal ratio remaining in a given specimen is given as well as its half-life. ▯ ▯ Chpt.19 — Introduction to Evolution ▯ •contrast homologous and analogous traits and their role in drawing evolutionary relationships homologous traits are brought about by divergent evolution, and it is when the same trait is seen in related organisms from a common ancestor, but because of divergence the traits have different functions in each species analogous traits are caused by convergent evolution, and it is when unrelated organisms have the same trait with the same function due to convergence ▯ • be able to explain how convergent evolution demonstrates the action of selection on organisms that are not biologically closely related, but have lived in similar environments the organisms have had to evolve to similar environments and ecological niches, which means that there may be similar favorable traits associated with each species ▯ •explain the difference between artificial selection and natural selection artificial selection: when the breeder chooses the parents (selective), similar phenotypes are more likely to mate, increases homozygosity natural selection: nature chooses parents, dissimilar phenotypes mate preferentially, favors heterozygosity ▯ •describe how phylogenetic trees help understand ancestral relationships between species they are based on similarities and differences between traits shared between the organisms; organized in a way that shows who evolved from which species ▯ •understand why phylogenetic trees drawn from molecular data show the same broad patterns as those drawn from fossil data DNA codes for mRNA which codes for proteins, and proteins produce physical traits. Organisms with similar DNA sequences are likely to also have similar physical structures. ▯ •understand why scientists look at the accumulation of neutral mutations rather than deleterious or advantageous mutations to determine how long ago two organisms diverged from a common ancestor comparison of the rates of accumulation of synonymous (no amino acid change) and non-synonymous (results in an amino acid change) changes can indicate selection. ▯ •describe the principle of natural selection and how it can lead to speciation individuals with heritable traits who are better suited to the environment have a reproductive advantage over individuals without such genetic variations. this can lead to speciation when over many generations, these advantageous traits are passed down, and the genetic changes in the species as a whole can become so great that a new species has evolved. the molecular clock is a chart that compares the number of amino acid differences in a specific protein between a selected group of organisms, those with fewer differences are more closely related than those with more differences. ▯ •explain how vestigial structures are compatible with Darwinʼs theory of evolution vestigial structures hang around because of evolution. At one time, they may have had a function in ancestral organisms, but they no longer have a function (or have changed function) in the current species. It shows that recent species evolve from a common ancestor. ▯ •explain how geography and embryology provide evidence for the theory of evolution Geography: the natural distribution of species across different continents supports evolution; species that evolved before the breakup of the supercontinent are distributed world wide, wheras species that evolved more recently are more localized. Embryology: provides evidence for evolution since the embryonic forms of divergent groups are extremely similar ▯ •understand why chromosomal rearrangements can present an evolutionary advantage for eukaryotic organisms chromosomal rearrangements are gross changes in chromosomal morphology, as opposed to small deletions or gene conversion. They provide an evolutionary advantage because rearrangements can result in new traits to make individuals more fit to the environment over time, higher survival rate and reproductive success. ▯ •describe the significance of how understanding the development of an organism in utero and underlying molecular biological mechanisms can help evolutionary biologists understand ancestral relationships developmental homologies are only visible during development (between birds, fish, reptiles, humans, all embryos look the same/similar) ▯ •be able to explain why the following statements are not accurate: ▯ 1. Evolution creates perfection. false because evolution makes organisms more adapted to their environment over time to increase survival rate and reproductive fitness, but it doesn’t make perfection because we are always changing to better survive ▯ 2. An individual evolves (in biological sense) false because evolution occurs in populations over a long period of time ▯ 3. Evolution is directional and has a purpose false because evolution has no direction and simply makes populations more likely to survive in a changing environment ▯ 4. Only the strongest member of the group survives false, those who are best adapted to their environment are more likely to survive ▯ 5. When we are taking antibiotics, a bacterial pathogen will develop resistance to it in order to survive. false because a single pathogen can’t evolve, but over time the population of bacteria could evolve to have antibiotic-resistant traits since the bacteria that survived the drug are more likely to reproduce ▯ Study questions ▯ 1) Specify how the process of selective breeding has led to various breeds of domestic animals and varieties of plants selective breeding is when a human selects the genes that he wants in the offspring, so dogs and plants can be modified with human intervention to have favorable traits, such as no shedding or plants that are pesticide-resistant ▯ 2) Compare and contrast anatomical, developmental and molecular homologies anatomical homologies: same origin, but can perform different functions (bone structure in vertebrates) developmental homologies: related species differ as adults, similarities show in the beginning of life during development molecular homologies: DNA similarities; every living cell contains plasma membrane, cytoplasm, and nucleic acid as genetic material; proteins have the same functions in every cell ▯ 5) Describe several ways that a species might acquire new genes. a species could acquire new genes through point mutations, insertions/deletions, duplications, or inversions. ▯ 6) What are homologous genes and what are some of the mechanisms that result in development of homologous genes a gene inherited by 2 species from a common ancestor (can be similar in sequence, but those similar in sequence are not necessarily homologousthose could be analogous) divergent evolution ▯ 7) What is a gene family? a set of several similar genes, formed by duplication of a single original gene, and generally with similar biochemical functions ▯ 8) What is the difference between ortholog and paralog genes? ortholog genes: comparing gene sequences from 2 unrelated species, homologous genes that are a result of a speciation event paralog genes: comparing genes from 1 individual, homologous genes that are a result of a duplication event ▯ 9) What is biological evolution? Be able to provide brief but complete definition descent with modification ▯ 10) List underlying molecular processes of evolution ▯ 11) Could a mosquito develop resistance to being killed by a chemical called DDT? Why yes, or why not? no, individuals do not evolve ▯ ▯ extra horizontal gene transfer- exchange of genetic material among different species karyotype comparison of human (46), chimp (48), gorilla (48), and organtuan (48) SNP-single nucleotide polymorphism (smallest change, most common) gene pool-all of the alleles for every gene in a population ▯ ▯ Chpt. 19 — Population Genetics ▯ •describe the characteristics of a population that is in Hardy-Weinberg equilibrium no mutations no natural selection no migration no sexual selection is in place (random mating) population is so large that random chance doesn’t affect allele frequency ▯ •outline the differences between allele frequency and genotype frequency and how each contributes to the Hardy-Weinberg equation freq. of phenotype/genotype= (x/ total number) freq. of allele= (number of copies of specific allele in population/ 2*total number) ▯ •be able to use the Hardy-Weinberg principle to calculate frequencies of specific phenotypes, genotypes and alleles p^2+2pq+q^2=1 p+q=1 p=frequency of dominant allele q=frequency of recessive allele p^2=frequency of homozygous dominant genotype q^2= frequency of homozygous recessive genotype 2pq=frequency of heterozygous genotype ▯ •be able to apply the Hardy-Weinberg principle to explain when microevolution occurs microevolution: changes in the allele frequency within a population over a span of generations macroevolution: changes in species composition over large amounts of time ▯ •explain how, and be able to compare and contrast the effect of mutations, gene flow, non-random mating, genetic drift, and natural selection have on evolution (in particular microevolution) mutations: random process, is not a major factor if not inherited and selected for in the entire population gene flow: any movement of individuals, and/or the genetic material they carry, from one population to another. If the gene versions are carried to a population where they previously didn’t exist, then gene flow can be an important source of information. non-random mating: o assortative mating-similar phenotypes are more likely to mate, homozygotes frequency increases o disassortative mating- dissimilar phenotypes mate preferentially, favors heterozygosity o inbreeding is related o not everyone is equally as likely to mate genetic drift: non-adaptive, random mutations in DNA, absence of selection, more obvious in small populations, in large populations, many more generations are required before an allele is eliminated or fixed natural selection: beneficial heritable traits that become more common in next generations, results over time in adaptations, promotes survival and reproductive success ▯ •describe the phenomena of bottleneck effect and founder effect and explain how they contribute to changes in allelic frequencies bottleneck effect: population reduced to a small size and eventually recovers, the reduced pop. is unlikely representative of the original population, caused by a random event (drought, flood, natural disaster) founder effect: small portion of the population is broken apart, genetic variation is lost and eventually an allele is lost or fixed in the smaller group because of genetic drift ▯ •why in some situations the phrase “survival of the luckiest” is actually correct After a natural disaster, it is not the fittest that necessarily survive, rather it is based on luck; the storm could kill those in a specific location, and the rest would survive, resulting in the bottleneck effect, and the resulting population would probably not be representative of the original population ▯ •describe how migration and non-random mating patterns affect genetic variation in populations migration o occurs between at least 2 established populations o increases genetic diversity in a population o movement of alleles in or out of the pop.=gene flow non-random mating o assortative/disassortative mating- mating with those phenotypically similar or dislike yourself, increase homo/heterozygosity in population o inbreeding: increases homozygosity and dangerous recessive traits ▯ •be able to name three kinds of natural selection and discuss the effect of each on a population (be able to give an example of each type, use the textbook for additional examples that were not given in lecture) 1. Directional selection: when natural selection favors one extreme of continuous variation. Over time, the favored extreme will become more common and the other extreme will be less common or lost o ex: if thicker-shelled oysters are more resistant to breakage than thinner-shelled oysters, the thicker-shelled will be less preyed on and will survive to reproduce 2. Stabilizing selection: when natural selection favors the intermediate states of continuous variation. Over time, the intermediate states become more common and each extreme variation will become less common or lost o ex: very light-colored or very dark-colored oysters might be more frequently preyed upon by shore birds, simply because they are more obvious on the oyster bar, so the intermediate hues become more common 3. Disruptive/Diversifying selection: when natural selection favors both extremes of continuous variation. Over time, the 2 extreme variations will become more common and the intermediate states will be less common or lost. This can lead to 2 new species. o ex: really light oysters blend in with the rocks, and dark ones blend in with shadows, so the intermediate ones could be preyed upon more ▯ •understand that reproductive fitness varies between genotypes and that some genotypes are more likely to contribute to the gene pool of the next generation vs. other genotypes due to their greater reproductive success. ▯ •explain why sexual selection is a form of natural selection those with the most attractive traits to the opposite sex, or those who are able to mate with more of the opposite sex, are more likely to produce offspring and pass on their genes ▯ •explain why intrasexual selection and intersexual selection causes the evolution of certain traits to occur differently in males and females of the same species intrasexual selection: competition between 2 organisms of the same gender to get a mate (males fighting) intersexual selection: members of one gender choose a mate from another gender to mate with (female picking a male) ▯ •explain what is meant by heterozygote advantage and give an example as a mean related to stabilizing selection, when the heterozygote is favored over either homozygote, like how in Africa, being heterozygous for sickle cell prevents malaria and is beneficial ▯ Study questions ▯ 2) Be able to distinguish between two populations, one that is in Hardy- Weinberg equilibrium and another one that is not ▯ 3) What population will be evolving, the one in Hardy-Weinberg equilibrium or the one that is not? evolution will occur in the population that is not in Hardy-Weinberg equilibrium ▯ 8) Create a list of pros and cons of monoculture on the population dynamics on crop plants. pros: easy to grow? cons: little genetic variation for pest or disease resistance, easy dispersal of pests and pathogens ▯ ▯ Chpt. 20 Origin of Species (speciation) and Macroevolution ▯ •explain the challenges in defining a species different species have different characteristics, including morphological traits, reproductive isolation, molecular features, ecological factors, and evolutionary relationships o can be difficult if hybrid forms of species are created or the species is asexual and doesn’t follow reproductive barriers ▯ •define the two types of reproductive isolating mechanisms prezygotic: prevent the formation of a zygote o habitat isolation-different species never come in contact with each other o temporal isolation- when species happen to reproduce at different times of the year o behavioral isolation- mating behavior and anatomy (singing different songs to attract a mate) o mechanical isolation (attempted mating)- morphological features such as size or incompatible genitalia prevent interbreeding o gametic isolation (attempted mating)- 2 species may attempt to interbreed, but the gametes fail to unite successfully postzygotic: block development of a viable and fertile individual after fertilization has taken place o hybrid inviablilty- when an egg of one species is fertilized by a sperm from another species, but the fertilized egg can’t develop past early embryonic stages o hybrid sterility (F1)-an interspecies hybrid may be viable but sterile o hybrid breakdown (F2)- interspecies hybrids may be viable and fertile, but the following generations may harbor genetic abnormalities that are detrimental ▯ •explain how speciation might occur when populations are in direct contact with one another sympatric speciation: reproductive isolation ▯ •differentiate between the two major theories related to the pace of speciation gradual speciation: species arise gradually through evolution of traits that distinguish them from ancestral forms punctuated equilibria: controversy, species arose suddenly and then remained in stasis, morphologically and geneticall stable for most of their evolutionary history ▯ •explain the components of the punctuated equilibrium hypothesis species traits relatively constant, interrupted by brief, sudden, and abrupt strong selective pressures ▯ ▯ Study questions ▯ 1) What are the factors of speciation? Is the process of speciation gradual or incremental? Is it easy to distinguish individuals that are separated by only few generations as separate species? genetic and environmental factors affect speciation rates speciation is a genetic event based on reproductive isolation reproductive isolation can arise due to chance events in the environment or from behavioral or morphological variation genetic factors can enhance reproductive isolation once initiated, enhancing the likelihood and rate of speciation ▯ 2) Explain how the disappearance of an allele or few alleles from a population can lead to speciation ▯ 4) Compare and contrast allopatric and sympatric speciation. Be able to provide examples for each. What leads to sympatric speciation? allopatric speciation: when a population becomes isolated from other populations and evolves into one or more species sympatric speciation: when members of a species that are within the same range diverge into 2+ different species even though there are no physical barriers to interbreeding ▯ 5) What is a hybrid zone? How is a hybrid zone related to different populations? A hybrid zone is a narrow geographic region where two genetically distinct populations or species are found in close proximity and hybridise to produce offspring of mixed ancestry. ▯ ▯ Chpt.23 — Plant Evolution and Diversity ▯ Learning outcomes: ▯ •Name several characteristics unique to embryophytes (=land plants) vascularity, seeds, flowers… ▯ •Compare and contrast the features of vascular and nonvascular plants vascular plants are bigger because the nutrients can be transported further and the vascular tissue helps support the plant ▯ •List adaptations that enable vascular plants to maintain stable water content waxy cuticle, 3D tissues, and apical meristems (actively dividing cells) ▯ • Know that mosses are non-vascular plants and that ferns have a vasculature but do not produce seeds ▯ •Know the meaning of tracheophyte, xylem, phloem, and stomata tracheophyte- vascular plant xylem- conducts water and minerals, supports plant structure, made of dead tissue, lignin in walls of vessels to give rigidity and waterproofing phloem- conducts organic molecules (from photosynthesis) throughout plant body stomata- ▯ •Know the definition of a seed and the difference between a seed, a gametophyte, and a gamete (egg/sperm) seed- embryo with nutrients around it so the plant can reproduce; contains genetic information; endosperm(3n) provides nutrients to embryo during early life stages of plants gametophyte-sexual form of a plant in the alternation of generations (n, haploid) like pollen (male) gamete (egg/sperm)- a mature haploid (n) male or female germ cell that is able to unite with another of the opposite sex in sexual reproduction to form a zygote ▯ •List three gymnosperm phyla flowerless, vascular plants with seeds can live in cold, dry environments conifers, ginkgos, cycads ▯ •Know critical innovations that lead to evolution of flowering plants (angiosperms) vascular plants with seeds and flowers flowers enhance reproduction/seed formation presence of seeds within fruits (enclosed seeds) enhance dispersal of seeds when atomospheric O2 levels rose (lowest CO2 levels), seed plants became dominant in the cooler, drier habitats created gymnosperms and early angiosperms were probably major sources of food for early mammals/dinosaurs ▯ •Know when angiosperms evolved relative to other modern plant phyla evolved most recently ▯ •Know the general structure of a flower and the flowering plant life cycle ▯ ▯ sporophyte (2n) mature flower gametophyte (n) pollen pollinates the flower and goes to the ovary gametophyte discharges sperm (n) into egg nucleus (n) zygote is formed (2n) endosperm (3n) seed is formed from embryo (2n) and seed coat (2n) seed germinates into mature sporophyte (2n) ▯ •Describe how diversification of flowers and fruits enhances seed production and dispersal we need flowers for seed production insects and hummingbirds pollinate with pollen from another plant we need fruit for seed dispersion o fruits can be adapted to attract animals to eat them, for wind dispersal, to attach to animal fur, or to float in water ▯ •Understand how humans created domesticated crops and how it relates to artificial selection creates new species ▯ ▯ vascularized, seeds, flowers ▯ moss, fern, ▯ ▯ Chpt.27 — Introduction to Flowering Plant Form and Function ▯ Learning outcomes: ▯ •Name the tissues, organs, and organ systems found in a typical flowering plant ▯ •Know the difference between the 3 different types of seed-to-seed lifetime (perennial, annual, biennial) perennial- live for 2 or more years and don’t have to produce seeds every year (trees) annual- die after producing seeds durist the first year (corn) biennial- store food during 1 year that fuels reproduction next year of life (root vegetables) ▯ •Explain what a meristem is and describe how it contributes to primary growth of a plant the actively dividing cells of a plant stem ▯ •Know that specialized cells are all derived from stem cells (either SAM or RAM) ▯ •List the three types of tissue produced by apical meristems and describe the function of each ▯ •Distinguish between xylem and phloem xylem- tracheids and vessel elements conduct water and dissolved minerals (nonliving cells/apoptosis) o stiff fibers in the wall of these elements (lignin/structural support) o unspecialized parenchyma thin-walled cells=ground tissue phloem- transports organic compounds and certain minerals, sieve tube elements (living cells), companion cells aid sieve tube element metabolism, parenchyma cells=ground tissue, supportive fibers ▯ •Describe the basic tissue organization of a stem and a leaf 1. dermis- epidermis, trichome (hairs), guard cells (stomata), root hair 2. ground- parenchyma, mesophyll, cortex, pith, endodermis 3. vascular- xylem, phloem 4. meristem- apical meristem, vascular cambium, cork cambium (root cell layers) endodermis- concentric single cell layer surrounding central vascular cylinder ▯ •Understand that plants have a high regeneration potential when compared to animal cells ▯ •describe the basic tissue organization of a root, a stem, and a leaf ▯ •know examples of modified leaves, roots, and stems. ▯ •understand the importance of chemical in plants and their high regeneration potential when compared to animal cells ▯ •explain the functional properties of the zones of a typical root ▯ •explain the function of root hairs to provide greater surface area for water uptake ▯ •explain how modifications to typical root structures provide selective advantages for some plants guard cells and trichomes can be found on stems too? ▯ Study questions ▯ 1) What are the characteristics that flowering plants share with other living organisms? ▯ 3) What is the difference between growth and development? ▯ 4) What is the diploid generation in a life cycle of a flowering plant? What is the haploid generation in the life cycle of a flowering plant? What is the difference between a seed and pollen? diploid=sporophyte= mature flower haploid= gamete, gametophyte=pollen endosperm=3n ▯ 7) Where would one find gametophyte with the plant? male gametophyte develops inside the pollen grain female gametophyte develops inside the ovule ▯ 8) What generation do leaves, stem and root belong to?- sporophyte? ▯ 9) How does a gametophyte differ from a sporophyte? haploid vs diploid? ▯ 10) Define undifferentiated (stem cells), specialized cells, tissue, organ, organ system, and organism. stem cells- cell type that is capable of giving rise to indefinitely more cells of the same type, and from which certain other kinds of cells arise by differentiation (meristem) specialized cells- dermis, ground, and vascular tissues ▯ 13) What is a meristem? Where are meristems found within the plant? What is/are the role(s) of plant meristems? found in the root of a plant actively mitotic cells cells remain totipotent- they can develop into any specific plant tissue at any point during the life of the plant these cells divide and produce all of the new cells in the plant ▯ 14) Compare and contrast seed with a fruit. fruit bears the seeds fruit develops from ovary of flowering plant seed contains embryo and can produce a new plant ▯ 15) One aspect of the growth of a plant is marked as apical-basal polarity. What does that mean? ▯ 16) You are examining cross sections of two plant organs prepared from the same plant. What feature will help you determine the organ each cross section was made from? For example, how would root and stem cross sections differ? stem cross section- vascularized tissue in bundles outside of central core root cross section- vascularized in central core ▯ ▯ Chpt.29 — Flowering Plants: Nutrition &Transport ▯ ▯ Know the basic properties of water crosses semipermeable membrane via osmosis polarity of water molecules forms hydrogen bonds with other molecules cohesion-each molecule attracts its neighbor via H-bonds adhesion- polarity of water molecules attracts them to other polar substances surface tension-water takes a shape that minimizes its surface area> water droplets ▯ Compare and contrast passive diffusion and active transport and explain how each is relevant in the transport of water, minerals and nutrients (organic compounds) in plants passive diffusion: no energy required, concentration gradient, osmosis (water) facilitated diffusion: aquaporins, transport water more quickly but still passive active transport: energy required, membrane potential is established through proton pumps which pump H+ ions out in order to form an electrochemical gradient leads to absorption of positive ions and co-transport of negative ions (passive) increase in intracellular solutes drives entry of water via osmosis (passive) or water channels called aquaporins ▯ Describe the tissues that are specialized in transport of water and nutrients in a flowering plant be able to explain what is considered to be a typical structure of a flowering plant root, stem and ▯ leaf in respect to the internal system that specializes in transport of water and nutrients xylem (water and minerals from soil) and phloem (dissolved organic compounds from photosynthesis) root- water enters root stem-vascularized bundles leaf- stomata open to release water via transpiration and take in CO2 ▯ • Explain why we describe the movement of water within the plant in terms of water potential, explain what is meant by water potential, turgor pressure (=hydrostatic pressure) the moist soil has a higher water potential than dry air, so water flows up the plant via transpiration always flows from high to low water potential ▯ • Describe how solutes affect water potential (prediction of direction of water movement in or out of the cell) solutes lower water potential, which is why water flows toward the more hypertonic environment. water molecules cant interact as much ▯ • Explain the difference between a turgid, a plasmolyzed, and a ▯ flaccid plant cell turgid: water entered into the cell, in a hypotonic environment plasmolyzed: water moves out of the cell, in a hypertonic environment flaccid: no net movement of water, isotonic ▯ • Explain how to predict the direction of the movement of water based on solute concentration water moves from high to low concentration, so it will move to the side with more solute to even out the concentration ▯ • Explain the role root hairs have in water/mineral transport root hairs provide higher surface area for water to be absorbed into the roots, so more minerals can be taken in as well ▯ • Describe the internal structure of the primary root and the role of different parts and specific structures (hair, cortex, cell walls, endodermis, ion pumps, specific channels/carriers, plasmodesmata, casperian strips) in the transport of water and minerals until they reach xylem elements within the vascular cylinder hair: surface area, transmembrane transport cortex cell walls- give structure, endodermis-molecular filter, only essential mineral nutrients can cross ion pumps specific channels/carriers plasmodesmata- channels between cells for molecules to pass through (called cell junctions in animal cells) symplastic transport casperian strips- specialized part of cell wall that helps with impermeability ▯ • Describe apoplastic and symplastic forms of tissue-level water & mineral transport within the root by addressing the advantages and disadvantages of each apoplastic- through plant cell wall symplastic- through plant cell cytoplasm ▯ • Explain the role endodermis has and in particular the Casparian strips endodermis- functions as a molecular filter Casperian strips- helps with impermeability ▯ *Explain the components of the “push-pull model” when it comes to the movement of water and nutrients in the plant push- root pressure pull- transpiration, negative pressure exerted by water potential ▯ • Explain the role of guard cells, their structure, transport and hormone (ABA) mechanisms that are involved in regulation of the opening/closing of guard cells stomata regulate gas exchange and H2O/nutrient uptake pores open and close mostly on bottom of leaves, some on top open to increase transpiration rate, close to conserve water light causes them to open ABA hormone (abscisic acid) presence makes guard cells close ▯ • Explain what is meant by the sink and source tissues in the plant source: leaf, site of photosynthesis where all the organic molecules are made sink: fruit, storage of photosynthetic products such as sugar, not photosynthetic, nutrients flow to fruit via the push from the phloem ▯ Study questions ▯ 7) Be able to explain the nature of the plant cell wall (what type of molecule assemble as a polymer) and its hydrophilic nature. cellulose ▯ 8) Compare and contrast phloem to xylem. phloem transport dissolved products of photosynthesis xylem transport water and minerals ▯ 9) How does water get into the xylem from the surface of the root? What are the roles of active and passive transport in the movement of water from the surface toward the vascular cylinder active transport pumps H+ out of the cell w/ proton pump, then ions diffuse passively into the cell bc of an electrochemical gradient. there is a higher concentration inside the cell, so water moves in to balance it out water moves into the root hair by osmosis, then travels either o apoplastically through the plant cell walls, then transmembrane, then symplastic into the endodermis to the pericycle and vasculature,(quicker, most water goes this way) or o transmembrane transport through the plasma membrane of root hair cells, then symplastically through the plant cell cytoplasm, moving between cells using the plasmodesmata junctions, and into the endodermis>epicycle> vasculature ▯ 10) One of the working hypothesis that are providing explanation of the movement of the water in a flowering plant is referred to as a “pull & push” type of action. What is meant by using this simple phrase to describe the movement of water within a plant? pull of negative pressure from transpiration, push of root pressure ▯ 11) How does the chemistry of water molecules and the chemistry of cell walls contribute to the movement of water and solutes in the plant? cellulose is hydrophilic and water is attracted to it, so it is able to adhere to it when it is transported up the xylem and in the root, which transports nutrients with it, also water molecules are attracted to each other by cohesion ▯ 12) Once water gets into xylem elements what forces contribute to its movement toward the tips of shoots? negative pressure cohesion-tension theory- the cohesion of water molecules and the tension exerted by atmospheric evaporation in the xylem high to low water potential ▯ 13) What are stomata and where in the plant are they usually found? What type of tissue stomata openings belong to? How do stomata function? pores that can close to conserve water under conditions of water stress and open when the stress is relieved bordered by a pair of guard cells, which when turgid with water, open the stomata to let water out, and when flaccid, close the opening open in response to sunlight close during the day when under water stress due to ABA hormone let CO2 in, let H2O out ▯ 14) Be able to explain the main events responsible for activation of guard cells and results in the opening of stoma. Also be able to describe the sequence of events that results in the closing of stomatal pores in guard cells, ABA binds to a membrane receptor, which elicits a Ca2+ second messenger, causing the guard cells to lose solutes and deflate ▯ 15) What creates positive root pressure? When would one expect to find the highest positive root pressure? at night, water passively enters the roots, pushing water up the xylem even when stomata are closed. water is pushed out of the stomata and beads on the leaf, called guttation ▯ 17) What is the most common nutrient, besides water, that is found in a sap that travels through phloem? sucrose, it can be concentrated up to 30% by weight ▯ 18) How is the sucrose that is made in chloroplasts of leaves transported to the cells of the root (sink tissues in general)? phloem transport is bidirectional moves from a sugar source (a place where sugar is produced by photosynthesis or by the breakdown of sugars) to a sugar sink (an organ which consumes or stores sugars) sieve tube members transport phloem sap uses active transport with a H+/sucrose pump when sucrose is loaded into the phloem the buildup of pressure at the source and the reduction of pressure at the sink causes water to flow from source to sink, carrying the sugar along with it ▯ 19) Explain the role of active and passive transport. How does the closeness of xylem and phloem help in the transport of dissolved sugars? The phrase that describes the mechanism of sucrose transport through the plant phloem is “pressure-flow”. Explain. ▯ 20) What is hydroponics? Is a plant able to live without soil? growing plants without soil, yes ▯ ▯ Chpt. 28 Plant Behavior (signal and transduction, Plant response to light and non- light stimuli) ▯ • describe the signal transduction pathway and its significance in plant behavior behavior is a response to a stimulus 1. receptor activation (stimulus) 2. signal transduction to nucleus 3. cellular responses (phototropism, defense, seed germination, flowering) 4. behavior ▯ • understand which type of stimuli plants are able to respond to in order to survive. light, gravity, touch (directional, tropic movements) ▯ • list potential environmental cues that could trigger a signal transduction event in a plant cell phototropism- growing toward a light source ▯ • compare physical and biological stimuli that could trigger response in plants biological: internal biological clocks, mobile chemical signals physical: light, gases, temperature, touch, wind, gravity, soil water, rocks, soil minerals ▯ • explain the involvement of plant hormones in signal transduction pathway and plant behavior in general ▯ • be able to explain the general mechanism in flowering plants that enables them to sense and respond to light (use example of stomatal pore opening in the morning detailed under Chpt.29) ▯ • be able to describe differences in responses to gravity in different parts of the flowering plant sporophyte ▯ ▯ Study questions ▯ 2) How have plants adapted to survive to a specific environment even though they cannot move and do not have eyes? ▯ 3) Be able to describe a signal transduction pathway within a cell from stimulus to response (in the correct order) ▯ 4) What is a nutation movement? What is a nastic movement? What is a tropic movement? What is the difference between these three types of movements? nutational: circular, slow, irregular growth nastic: non-directional, like closing and opening in response to light, independent of stimulus position directional: tropic movements, direction depends on stimulus position and is due to growth (light, gravity, touch) ▯ 5) How is a plant responding to changes in direction of gravity? positive gravitropism ▯ 6) What is the difference between positive and negative gravitropism? positive means going with gravity, negative is against gravity ▯ 7) Know what the words thigmotropism and thigmonasty mean and their difference. thigmotropism: touch-induced movement, like growing around a wall, pot, or trellis thigmonasty: mimosa closing its leaves due to touch ▯ ▯ Chpt. 25 & Chpt. 26 Introduction to Animal Diversity (Classification, ECM, and Animal Form & Function) ▯ • Be able to list main characteristics shared by all members of the animal kingdom heterotrophs- obtains all energy from covalent bonds of organic molecules by eating (none from photosynthesis except sea slugs and algae) presence of a nervous tissue for rapid response of the muscular system and movement most reproduce sexually multicellularity cells are flexible (no cell wall) can adhere and interact with each other ▯ • List and briefly describe critical innovations that have occurred in evolution of invertebrate and vertebrate animals symmetry, open/closed circulatory system, notochord, spinal column, segmentation ▯ • Explain the difference between radial and bilateral symmetry and give examples of animals that display these two body plans bilateral- human, left and right sides are symmetrical radial- sea urchin, circular symmetry ▯ • Know that Mollusks, Annelids, and Arthropods are protostomes ▯ • Know that echinoderms (starfish) and chordates are both deuterostomes ▯ • Know that squids, octopi, mussels, snails belong to the Mollusca phylum ▯ • Know that earthworms belong to the Annelida phylum ▯ • Know that crustaceans (crabs/lobsters) and insects belong to the Arthropoda phylum (=most successful animal phylum) ▯ • Describe the advantages of segmentation (use the information from the dissection of invertebrates) it allows specialization of body regions and the appendages used for movement ▯ • Know that all animals evolved from a single common ancestor (=monophyletic kingdom) ▯ • Understand the meaning of the terms chordates and vertebrates chordate: notochord, dorsal hollow neural tube, not all chordates are vertebrates vertebrate: chordates with a backbone, endoskeleton, and way more ▯ • Be able to list at least five features that most vertebrates possess but invertebrates do not 1. vertebral column, cranium, endoskeleton 2. jaws 3. bony skeleton, lungs or lung derivatives 4. lobed fins 5. limbs 6. amniotic egg 7. milk, hair ▯ • Know the order of appearance of critical innovations in vertebrates 1-7 above ▯ • Be able to distinguish cartilaginous fishes (shark) from bony fishes ▯ • List adaptations that permitted the transition from aquatic to land life and give an example of animal living between water and land (=semiterrestrial lifestyle) amphibians live in both land and water they can breathe through spiracles in their skin, or through nostils/mouth ▯ • Understand why a dessication-resistant amniotic egg permitted life on land a shelled egg protected the embryo, allowed animals to lay their eggs on land in a dry place without them drying out, reproduction was no longer tied to water ▯ • Know that reptiles include lizards, turtles, snakes, crocodilians, and BIRDS! ▯ • Be able to list at least three features that separate mammals from other vertebrates mammary glands producing milk for newborns hair specialized teeth enlarged skull ▯ • Understand the difference between gap junction, tight junction, and anchoring junction and the role they play in cell-cell contact/communication gap junction: directly connect the cytoplasm of 2 animal cells, allow molecules, ions, and electrical impulses to directly pass through a regulated gate tight junction: seal adjacent epithelial cells in a narrow band just beneath their apical surface, limit passage of molecules and ions through space between cells anchoring junction: link cytoskeletal proteins to other cells and to ECM ▯ • Explain the relationship between form and function, and provide several examples of anatomical structures that demonstrate this relationship/describe the importance of surface area-to-volume ratio when considering transport of substances into and out of cells and entire organisms ▯ ▯ Study questions ▯ 1. Describe similarities and differences between metabolic needs of animals and plants, know the difference between autotroph and heterotroph and list the three main types of feeding in animals (suspension/filtering; bulk; fluid) animals need more energy, higher metabolism, heterotrophs, eat food and break covalent bonds for energy plants are autotrophs, make their own energy from photosynthesis suspension/filtering: filtering food out of the surrounding water bulk: eating large food pieces fluid: sucking plant sap or animal body fluids ▯ 2. Is mobility a necessary criterion for categorizing an organism as an animal? Explain most animals are capable of some type of locomotion in order to acquire food or escape predators ▯ 4. Explain the difference between a cavity (sponge) and a true body cavity (coelum in coelomates) coelomates- animals with a true body cavity, like annelids, arthropods, and chordates psuedocoelomates- if the fluid-filled cavity is not completely lined by tissue derived from the mesoderm (rotifers, nematodes) acoelomates- lack a fluid-filled body cavity, such as flat worms ▯ 5. Explain at least two features that distinguish protostomes from deuterostomes protostomes- during embryonic development, the blastospore becomes the mouth; determinate cleavage during development, meaning the fate of each embryonic cell is determined early deuterostomes- the blastospore becomes the anus; indeterminate cleavage, meaning each cell produced by early cleavage retains the ability to develop into a complete embryo ▯ 7. List four types of tissues and provide at least 2-3 examples of each type of tissue ▯ 8. List few organs and explain the types of tissues that form each organ ▯ 9. What is the difference between an epithelial tissue and a connective tissue? ▯ 10. What is the name of the structures that permit communication between two animal cells? gap junctions? ▯ 11. What is the most abundant glycoprotein located in the extracellular matrix (ECM) of most animal cells? collagen ▯ ▯ Chpt. 31 Animal bodies and Homeostasis, Energy Balance, Metabolic Rate & Thermoregulation ▯ • Explain the difference between a regulator and a conformer regulator: endotherm, like a bird or mammal conformer: ectotherm, conform to the environment’s temp., like reptiles, amphibians, insects some fish that are temperature conformers but they regulate internal chloride levels ▯ • Know the definition of homeostasis process by which organism remains internally stable no matter what happens on the outside of the body ▯ • Understand how homeostasis is maintained and the main difference between animals and plants (brain/central control=integrator) plants [stimulusreceptoreffectorresponse] animals [stimulusreceptorcontrol centereffectorresponsefeedback mechanism (negative or positive)] ▯ • Know the meaning and difference between a negative and a positive feedback loop ▯ • List the four types of heat transfer conduction convection radiation evaporation ▯ • Know the meaning of the following terms: homeotherm, heterotherm, poikilotherm, endotherms, ectotherms, conformers, regulators (be able to give examples of animals for each category) homeotherm/endotherm/ regulators- regulate internal temp., regulate amount of heat generated by internal oxidative reactions and control the rate of heat exchange with the enviornment heterotherm- animals that exhibit characteristics of both ecto and endotherms poikilotherm/ectotherm/ conformers-have to find optimum temp. because they conform to external temperatures, primarily control the rate of heat exchange with the environment, but this is a problem when temperature changes are large ▯ • Provide examples of how changes in temperature affect the way an animal’s body is able to function in ectotherms, when temperature ^, their metabolism ^, and vice versa in endotherms, their metabolism is most efficient at a critical temperature, and when they get too low or too high, their metabolism raises to retain homeostasis ▯ • Be able to describe mechanisms and adaptations demonstrated by animals to adjust to temperature extremes sweating to cool off, shivering to warm up torpor (daily) during cold nights, the whole body slows down, lower body temperature hibernation during cold seasons when food isn’t available ▯ • Provide advantage and disadvantages of being an endotherm, an ectotherm endo: + your activity level is independent of temperature ecto: + you don’t need to eat a lot of food ▯ • Be able to define metabolic rates in endotherms and ectotherms (BMR vs. SMR) BMR: basal metabolic rate, in mammals and birds, the stable, fasting, minimum rate of metabolism required for life, increases when the organism strays from optimal temperature zone SMR: standard metabolic rate, the minimum metabolism of fasting animals at a given external temperature, in these animals, SMR is highly dependent on the environment (high temp=high metabolism) ▯ • Explain the effect of exercise and food intake on basal metabolic rate (BMR) exercise increases metabolic rate because the internal body temp is raised and the body has to work harder to cool it down ▯ • Understand that larger animals have slower metabolic rates relative to smaller animals when basal metabolic rate is normalized to their body mass (mass-specific BMR). surface area/volume ratio smaller animals have higher metabolic rates because they have a higher surface area for their mass and volume ▯ • Be able to distinguish an endotherm from an ectotherm based on values of metabolic rates measured at different temperatures ▯ ▯ Study questions ▯ 2. Explain how a regulator could maintain body temperature within a certain range in spite of changes in the environment they change skin blood flow, sweat, shiver, and have behavioral adaptations internal oxidative reactions ▯ 3. Why is it important that an organism maintains its temperature at an optimal temperature and not above or below? too high- proteins denature too low- plasma membrane loses fluidity ▯ 6. How does an ectotherm adapt to an increase in temperature? What about an endotherm? ectotherm would seek a cooler environment, can’t cool their own body down endotherm would have a slightly raised metabolism as it sweat to lose heat from the body and maintain homeostasis ▯ 12. How does an animal’s diet affect its BMR? ▯ ▯ Chpt. 32 Nervous System ▯ • Describe and list the cellular components of the nervous system and their function neurons- excitable cells that transmit electrical signals o don’t divide o high metabolic rate neuroglia (glial cells) supporting cells o astrocytes (CNS)- do a lot, most common o microglia (CNS)- defensive o ependymal cells (CNS)- separate CNS interstitial fluid from the cerebrospinal fluid in the cavities o oligodendrocytes (CNS)- processes wrap CNS nerve fibers, forming myelin sheaths o Satellite cells (PNS)- surround neuron cell bodies in PNS o Schwann cells (PNS)- form myelin sheaths around PNS fibers ▯ • Name the components of the nervous system (CNS vs. PNS) CNS- brain and spinal cord PNS- everything else ▯ • Know the meaning of an afferent and an efferent nerve signal(PNS) afferent is sensory, goes toward the spinal cord to be integrated in the brain efferent is motor, transmits impulses from CNS to effector organs ▯ • Know that sodium extracellular concentration is higher than its intracellular concentration and that it is the opposite for potassium, and that the concentration of anionic macromolecules is higher inside of a typical neuron sodium is higher outside the cell potassium is higher inside the cell inside of the neuron is negatively charged ▯ • Explain what the membrane potential is difference in ion concentration between the inside and outside of membrane exists in all living cells Na+ and K+ ions are important to establish a membrane potential in animal cells inside, lower concentration of Na+ and Cl- than outside inside has more K+ and negatively charged proteins than outside ▯ • Explain how the resting potential is maintained resting potential is -70mV more of potassium K+ channels letting K+ out than Na+ ungated channels (passive) sodium-potassium pump (3Na+ out for every 2 K+ in) (active) negative ions located by the membrane, proteins inside are negatively charged ▯ • Explain the difference between the membrane potential every alive cell has and specialized properties nerve, muscle, and bone cells have • Compare channels to pumps channels are passive, with concentration gradient or electrical charge pumps are active, use ATP and go against gradient ▯ • Explain the role myelin sheath surrounds axons and transmits the action potential more quickly insulate and prevent leakage of charge ▯ • Explain how action of voltage-gated channels produces an action potential ▯ • Compare and contrast graded potentials and action potentials graded potentials: incoming short-distance signals, short-lived depolarizations or hyperpolarizations o occur when a stimulus causes gated ion channels to open o mainly in sensory neurons action potentials: long-distance signals of axons o brief reversal of the membrane potential with a total amplitude of ~100mV o occurs in muscle cells and axons of neurons o does not decrease in magnitude over distance ▯ • Explain how signal travels through the neuron dendrite soma axon axon terminal ▯ • Describe how nerve signal crosses from one neuron to another neuron ▯ • Explain what a synapse is junction where nerve terminal meets a neuron, muscle cell, or gland, can transmit electrical or chemical impulses EPSPs can increase the likelihood of an action potential in the postsynaptic neuron, while IPSPs have an inhibitory effect ▯ • List the classes of neurotransmitter and a brief description of how neurotransmitters usually function Ach biogenic amines (small) histamine, serotonin, epinephrine, dopamine amino acids- glutamate, GABA neuropeptides (endorphin-opiate peptides) gaseous neurotransmitters (nitric oxide) ▯ • Describe possible effects on the body of disorders in neurotransmission multiple sclerosis – myelin sheaths in CNS become nonfunctional scleroses ▯ ▯ Study questions ▯ 1) Review the properties of membranes. How does the structure of the membrane relate to the properties of the membrane like semi-permeability? impermeable to negatively charged proteins slightly permeable to Na+ (through ungated channels) 75 times more permeable to K+ (through ungated channels) freely permeable to Cl- the negative interior of the cell is due to much greater diffusion of K+ out of the cell than Na+ diffusion into the cell Na+/K+ pump stabilizes the resting membrane potential by maintaining the concentration gradients for Na+ and K+ ▯ 6) Explain what force(s) contribute to the movement of ions across the membrane if appropriate channels are open? non-gated channels- always open gated channels- o chemically gated (ligand-gated) channels: open with binding of a specific neurotransmitter o voltage gated channels- open and close in response to changes in membrane potential o mechanically gated channels- open and close in response to physical deformation of receptors when gated channels are open, ions quickly diffuse across the membrane along their electrochemical gradients (from high to low concentration and toward opposite electrical charg
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