LS1: Midterm 1 Study Guide
LS1: Midterm 1 Study Guide
Popular in Course
Popular in Life Science
verified elite notetaker
This 13 page Bundle was uploaded by Shreya Sreekantaswamy on Monday April 21, 2014. The Bundle belongs to a course at University of California - Los Angeles taught by a professor in Fall. Since its upload, it has received 920 views.
Reviews for LS1: Midterm 1 Study Guide
Report this Material
What is Karma?
Karma is the currency of StudySoup.
You can buy or earn more Karma at anytime and redeem it for class notes, study guides, flashcards, and more!
Date Created: 04/21/14
LS1 MIDTERM 1 REVIEW THE SCIENTIFIC METHOD 0 you CAN39T prove or disprove anything only gather evidence to SUPPORT or REJECT a hypothesis 0 Correlation does NOT imply causation o Ex even though some people develop ulcers when stressed that doesn t mean that stress causes ulcers ulcers are caused by the bacteria H pylori oTheory general explanation of natural phenomena supported by many if resrulits are not consistent reject or revise experiments and observations h th in Wm M 0 Ecology the study of how organisms interact with one another and with the Equot39 39f39quot f physical environment in nature S8 U ti Fli a M 3 U 5 o Ex Animals eat fruit and then disperse seeds through defecation if a if results are consistent 0i39vE T many eiperiiriients mutation makes a fruit more appealing then it will be selected for so hypothesis becomes a tlieorii that it is more likely to be eaten and have its seeds spread o Humans are affecting ecology by helping some species corn cockroaches rats and led others to extinction or the brink of extinction Bengali Tiger and White Rhinoceros EVOLUTION 0 Early ideas o Charles Lyell wrote Principles of Geology gradual changes occurring in the present create large changes in the future I Ex Himalayas rising by 1 cm a year gt over millions of years would rise high o JeanBaptiste Lamarck use or disuse would lead to trait alteration in an individual over a lifetime I But we now know that ACCQUIRED TRAITS CAN39T BE INHERITED only genetic traits can be passed on to offspring 0 Darwin o On the Voyage of the Beagle Darwin documented everything he observed amp collected fossils and specimens o Saw evidence of Lye s quotgradual changes leading to larger amp also noticed patterns in observations o Darwin read Thomas Malthus An Essay on the Principle of Population I Malthus said 1 Populations grow exponentially resources do not 2 Population growth is eventually checked by famine and disease o Darwin analyzed selective breeding artificial selection evidence of similarities between species o Darwin39s ideas were very controversial I People believed that God created life as is Darwin was reluctant to go against beliefs 0 Alfred Russel Wallace o Developed same ideas as Darwin o In order to not lose credit on the ideas he had developed Darwin proposed to co author paper with Wallace I Paper presented to Linnean Society in 1858 Wallace only briefly mentioned 0 Darwin published On the Origin of Species by Means of Natural Selection 1859 o Showed that species changed over time and suggested that mechanism was adaption via natural selection o DARWlN S THEORY OF NATURAL SELECTION I All populations have ability to grow exponentially I Resource limitation prevents exponential growth I Variation exists within population I Variation in population is heritable EJ39 I lI39IEI39I Ell I Resource limitation results in logistical growth as near carrying capacity I Carrying capacity K maximum a population can grow given resources in F39ripuat139irin 5iiE in environment Tiime 1 I Variation in organisms in population leads to different survival rates I Fitness extent to which individua s alleles are present in next generation 0 Greater fitness means organism is better adapted to survive in environment and therefore more likely to have offspring that also survive have parental alleles 0 Evolution change in allele frequencies in population over time o Natural selection MECHANISM that causes evolution o Evolution acts ON INDIVIDUALS and thus changes the POPULATION o Individuals can ACCLIMATE to environment no genetic change but populations ADAPT genetic change 0 Requirements for Natural Selection o Limited resources o Variation in population o Fitness different rates of survival and reproductive success for individuals in population o Genetic changes over many generations 0 The Modern Synthesis current theory of evolution combination of information from o 1Darwin s natural selection o 2 Mende s study of pea plants o 3 fact that variation occurs along a spectrum harmful neutral advantageous amp that multiple genes are responsible for controlling traits 0 Natural selection product of 1 genetic variation of population 2 fitness 3 heredity o Population adapts to conditions of environment at that time 0 The following statements about natural selection are FALSE o It has goals and is all powerful I Just adjusting at the time and not working towards a longterm quotperfection It produces what is quotneeded or quotwanted Plants and animals quottryquot to evolve It produce perfection OOOO It is random 0 Types of selection cairnoiu aged agiairist the backgroiunci suiirvive ainci reproduce whereas those that do not are eliiniriated by k k piredatoira U1 Tu ll 3 F 5 Original How does selection a ect tins E populationi distriijutiori of piwenotypes in three enviroririnems in Wlhifll 1 the iaackgrourid colors differ E In eaiclh case lizards that are 3 tr E Ll Phenotypes skin colorl Origiinali P39oipiiiatiori liliese popiilation after iif lClliV39idLlallS selectioin are selected agaiinst 9 s GU r V 0bV U 0j Stabilizing selection selects Directional selection selects Disruptive selection selects b agaiinsst itlie extremes against oine ofthe two extremes against the niean 0 Human birthweight stabilizing selection because extremes at both ends die EH 3iiiiiri an an 15 an a F39erIiEI39Il ngf pieipulaitinn with given blrtlwreight and iuI39li El HI i39Pquot1quotlquotquot Ilriiamliuiq llli lifi e rte sagqeiqi yr iiuvaagad irl II weiglfrt itg FlgIIII2El2I EIi39qrr39IaquotIJi39 39equot39iIaI a E39I2IdiquotJ Iii39Iiii39quoti391rlEC iirquoti 0 Artificial selection form of directional selection 0 Intentional breeding of plantsanimals by humans that selectsfor positive traits and against negative ones I Ex developed wild mustard plant into kohrabi kale broccoli brussels sprouts cabbage cauliflower I Ex bred variety of present dogs by selecting for traits in wolves 0 Molecular Evolution accumulation of different mutations in different populations 0 Early methods of measuring variation in a population 0 Observable traits 0 Gel electrophoresis initially could only detect variation in enzymes 0 DNA sequencing MECHANISMS OF EVOLUTION 0 Microevolutionz change in relative allele frequencies of alleles in gene pool over time 0 MECHANISMS FOR EVOLUTION o Natural Selection I If phenotype aids in survival then will be selected for against if harmful either one leads to change in allele frequencies I Alleles can become fixed in population at frequency of 1 every member has it or 0 no allele for the trait is present in the population I Balancing Selection two or more alleles are maintained in the population 0 Ex one population has certain characteristics that are beneficial in dry environment another in wet BUT SPECIES AS A WHOLE IS BALANCED 0 Since maintaining allele frequencies NOT A FORM OF EVOLUTION but maintains variation required for evolution 0 Heterozygote Advantage form of balancing selection where heterozygote has higher fitness than either homozygote o Ex individuals that are heterozygous for sickle cell anemia have some sickled cells but not all are resistant to malaria o Mutation change in genetic material that provides novel new genotypes I Can occur in somatic body cells or germ reproductive cells I can be beneficial deleterious harmful or neutral I random and slow evolutionary process I occurs during recombination in meiosis I Meiosis process of producing gametes 0 Yields 4 daughter cells that are EACH GENETICALLY UNIQUE 0 Each daughter cell contains HALF the number of chromosomes as parent 0 Law of Independent Assortment alleles of one gene assort independently during gamete formation leads to genetic diversity o Genetic Drift random changes in allele frequency that occur due to sampling errors I More apparent in small populations I Bottleneck event rapidly leads to only few remaining individuals of initial population 0 Ex Northern Elephant Seals hunted to near extinction now brought back but with greatly reduced genetic diversity I Founder Event colonize area with small group of individuals from population o Gene Flow movement of alleles from one population to another through migration I Eventually leads to homogenization of allele frequencies o NonRandom Mating I Sexual selection ex peahen chooses peacock based on elaboration of feather display and dance 0 HardyWeinberg Equilibrium acts as null hypothesis and suggests Let p a dominant allele that population IS NOT evolving Let q a recessive allele 0 Aquote39e fquote equot V P quot39 q 1 Therefore pq represents a heterozygote o Genotype frequency p2 2pq q2 1 o Assumptions I NO natural selection no difference in survival or reproductive success of individuals I NO mutations I NO genetic drift ie should be a large population OPPOSITE of Evolutionary Mechanisms I NO gene flow ie no migration I Random mating SPECIATION 0 When naming a species list Genus name first and then species name always italicize 0 Biological Species Concept BSC species are groups of actually or potentially interbreeding populations that are reproductively isolated from other such groups o May be physically separated but still be part of one species if can reproduce when brought together o Must be reproductively compatible and produce fertile offspring o Hard to implement I Extinct organisms I Asexual organisms I Two organisms from same species may simply choose to not breed 0 Morphospecies Concept members of the same species usually look alike o Not always true I Polymorphic species several different forms among members of same species 0 Ex pheasants are sexually dimorphic males and females appear very different I Cryptic Species members of different species that look very similar usually but not always due to a chromosomal difference I Ring Species members of two populations can39t directly interbreed but breed with other populations that breed with each other and therefore CAN indirectly interbreed so are NOT different species 0 Ecological Species Concept members of a species are characterized by their ecological niche habitat requirements nutritional and water needs etc o 2 species with very similar niches can39t co exist in same location 0 Evolutionary Phylogenetic Species Concept members of a species all share a common ancestor and a common fate o Good for differentiating asexual species 0 Reproductive Isolation o PreZygotic Factors prevents fertilization I Spatial Isolation 1 geographic location 2 ecological different niches I Temporal Isolation isolated in time ex flowers bloom at different times I Behavioral Isolation species have different mating callsdances I Mechanical Isolation quotlock and key concept that reproductive organs of different species especially insects don t fit together o PostZygotic Factors mating produces individual that is not viable might not survive or not fertile I Ex Horse Donkey Mule can39t mate with either parent species I Ex lion tiger in captivity 0 Speciation occurs when two populations have genetically diverged to the point where they can no longer produce viable fertile offspring very gradual process 0 Allopatric Speciation speciation that results from the physical separation of a population o Dispersal some individuals leave population to colonize far from main group I Peripatric Speciation few individuals from mainland population disperse to new location and evolve separately results in isolated ISLAND POPULATION 0 Slightly different environment small population genetic drift leads to faster change accumulation 0 Ex New Guinea kingfishers more genetic divergence among island populations than mainland o Vicariance geographic barrier arises that separates single population I Ex Albert Squirrel and Kaibab Squirrel separated by Grand Canyon have become different species I Ex marine life between Caribbean and Pacific used to interbreed then separated by Panama 0 Now have become different species but sister species is one on other side of isthmus o Adaptive Radiation rapid evolutionary diversification in which natural selection accelerates the rates of both speciation and adaption I Rapid speciation to fill all available niches I Ex Galapagos finches different beaks adapted to different food sources 0 In case of finches also includes peripatric speciation as a component but this is not always the case 0 Number of species of finches increased as more islands appeared 0 Cospeciation speciation that occurs in one species in response to speciation in another o Parasite and host phylogenies are often very similar 0 Sympatric Speciation speciation among populations of the same organism that are NOT geographically separated o Have initial gene flow between diverging populations o Controversial because since living in same location would expect some sort of gene flow o However might be separated temporally I Ex apple maggot flies developed from hawthorn flies even though live in same area are now different species both fruits are in season at different times temporal o May result from disruptive selection 0 Instantaneous Speciation 2 species produce a viable offspring but it is a hybrid new species that is reproductively isolated from both parents o Result of Polyploidyz change in chromosome number between parent and offspring o Most often occurs in plants o Post zygotic factor ex mule 0 Reinforcement of Reproductive Isolation diverging populations undergo natural selection in favor of enhanced pre zygotic isolation to prevent production of lessfit hybrid offspring o Select for traits that increase differences PHYLOGENIES Hypothesizes evolutionary relationships 0 Taxonomy species gt genus gt order gt class gt phylum gt kingdom gt domain o Family between order and genus may be divided into subfamilies Display similarities and differences in characters traits o 1 morphology formstructure 2 physiology function 3 behavior 4 genetics Sister species species that are more closely related to each other than either one is to any other group Nodes can be rotated without changing evolutionary relationships 5W BMgmmHE Phylogenies are built by observing shared derived traits o Synapomorphies characters traits shared by some but not all of the members of the group LengmuarhranhaesmIuunnaryd39utanne under consideration r V l39ia395l I39iIiJil1 IEil39l group la39uall irIaiLIla1H11n1nI1aiIIEta pX v 1 39ni ii i 5 and allnrimuu aemianm y E m dEquot5 L Y J EaE Iiiliian5 FFEIEIlI39E B IiEgjl39llIZI quot39yEII1 Turtles 39I39illZllIil2E En39i39I39I39IeEI39i3Ul2rE 2iEI39 A mdsmelmmm min Lmmds and snakes p ih deiemaam Grsudliles and quot39 h alliiatirs 39PnIrnhyIeiarnuniredii A Birds Flying IZIEIZIIEI39EEEI l2iI39Hlil2iEquotl239IeE III39I1lI39il l39I Z Z 39ljE39r 5 hEl39ilsEElZEi39 A Fl ullIEIJI sr g1 1amI391 t 39a H r ii 339 ii IEIfI r gu nquotlI 39 El I a quotlII 0 Monophyletic Group Cade o Organisms in a clade have Homologous Traits similar traits with a common ancestry I Only homologous traits are used to construct a phylogenetic tree Polyphyletic Group 0 Organisms in group display Analogous Traits Homoplasy similar traits that evolved independently organisms do NOT have a common ancestor I Ex birds and bats evolved wings but don39t share a common winged ancestor I Development of analogous traits is referred to as Convergent Evolution Often several Phylogenetic trees serve as plausible explanations for organism relatedness o In this case use Parsimony most likely explanation requires the least number of changes for the organisms simplest tree o Can make phylogeny using synapomorphies based on gene sequences compare species to out group Molecular Clocks measure genetic divergence between species as a function of time since species began to diverge o Some genes acquire differences at slowerfaster rates than others o Pick the gene to observe as one that doesn39t change too fast or too slow medium rate FOSSILS remains of once iving organisms preserved through time in sedimentary rocks 0 Bias in fossil record 0 Habitat fossils are most easily formed in marine environments with soft sediment o Taxonomic amp Tissue only quothard parts of an organism are preserved usually don39t find fossils of quotsoft organisms like jellyfish Temporal Abundance organisms from large populations are more likely to be fossilized than ones from smaller populations due to sheer number of individuals 0 Trace Fossils fossilized tracks and trails from animals as they moved or burrowed into sediment 0 Molecular Fossils sterols bacterial lipids and some pigment molecules that can accumulate in sedimentary rock documents animals that rarely form conventional fossils 0 Relative Dates since organisms are preserved in layered rock can compare the layers to each other to determine the relative age of the species that was fossilized 0 Radiometric Carbon Dating 0 14C in CO2 is incorporated into plants via photosynthesis 0 14C transfers to animals when they eat the plants 0 When the organism is died and buried 14C decays to 14N I Rate of decay is called Halflife 5730 years for 14C 0 Important dates 0 4567 million years ago formation of Earth quot4000 million years ago first evidence of life quot2500 million years ago first evidence of an oxygen rich environment quot542 million years ago first animal fossils quot250 million years ago first mammals OOO 0 Fossils show evidence of o Homologous Characters bone structure that is similar across several organisms I Ex Humans cats whales and bats have a similar arm structure 0 Vestigial Traits reduced or incompletely developed structures with little or no function I Clearly similar to structures that exist in other organisms I Provides insight into relatedness across taxa I Ex in humans the appendix is vestigial o Transitional Forms fossilized organisms that exhibit traits common to both ancestor groups and modern derived groups I Ex Tiktaalik is a transitional form between fish and tetrapods I Ex Archaeopteryx shows evidence of relation of birds and reptiles o Adaptions over time I Ex evidence of whales nostrils moving to the top of their head as they developed increasingly aquatic lifestyles 0 Mass Extinctions end of previously important species opens up new niches for those that survive leads to adaptive radiation with newly opened niches 0 End of Cretaceous Period eliminated all dinosaurs except birds lead to age of mammals 0 End of Permian Period eliminated 90 of genera I Extinction was a result of 1 lack of O2 2 ocean acidification 3 global warming because of volcanic eruptions 0 Burgess Shale found in British Columbia sedimentary rock formation during Cambrian Period 505 million years ago o Unusual condition that preserved fossils of unusual quality 0 Messel Shale found in lake in Germany released toxic gases 50 million years ago 0 Preserved birds fish reptiles plants and animals even with fur and color pattern impressions CARBON CYCLE 0 Carbon makes up 47 of dry mass in human cells 0 Found in nucleic acids amino acids proteins carbohydrates lipids 0 Cycles both carbon and H20 evolved before plants were on earth and was based in microbes 0 Ice cores provide record of ancient CO2 levels in the atmosphere 0 Air bubbles retained in the ice captured isotopes that were present when the ice formed 0 Showed that CO2 outputs and inputs were in balance until the Industrial Revolution 0 Vostok ice core shows that on long time scaes CO2 variation can be large 0 Mauna Loa Observatory records current atmospheric CO2 levels 0 Shortterm Carbon Cycle 0 CO2 concentrations regularly cycle up and 39i 1vE mEEI1h39 i39ilD 5 rseguu Iiarhr IIrIIe Imp and IlIrInrIIIII mner 1e E lIIr5E39 Inf 3 fear 39339El iI1li39I3939iI39il1I down over the course of the year matching up with times of increase photosynthesis I Since there is more land mass in the Northern Hemisphere CO2 levels 39 V P Fhnmsynnhesh leaI show a general during the northern i lSED3 HiV2 t I Equot5llui393I5I rE39I1 5 summer due to increased rates of CID iJlllI39IIIIEl39I39IIzI ifiillII39ll ppmfl R95lquoti39 3quot quot J ph0 E0SVn EheSiS Fl 5hlZllquotl II39 steadIjrincreaae Izwer gm J 0 the last Elfl years 0 Longterm carbon cycle carbon cycles throughout W quotquot39 quotquotquot 39 W quot W biosphere by moving through reservoirs O O O Reservoir place where carbon resides on Earth Flux rate at which carbon flows from one reservoir to another Carbon Source adds carbon into atmosphere I Volcanoes I Anthropogenic Sources made or generated by humans 0 Deforestation burning of fossil fuels 80 of CO2 annual human additions 0 50 of anthropogenic CO2 ends up in atmosphere Carbon Sink reservoir that holds and absorbs carbon for later use longterm carbon storage I Shells and coral skeletons store carbon as calcium carbonate CaCO3 I Subduction Zone place in Earth39s crust where one tectonic plate goes below the other one acts as carbon source for volcanoes I Not considered a carbon sink if temporary carbon storage that can be released easily I Reservoir size living organisms lt atmosphere lt soil ltsedimentary rocks Chemical Weathering chemical reaction between air and exposed rocks that removes CO2 from the atmosphere and deposits it in the oceans as CaCO3 ifiItEil397gi il3iEli Glacial Biomineralization precipitation of minerals by an H S II Ii E iii Ilia I organisms C02 gt CaCO3 r ML J IIii N 39IWII lI39Wwm I E gzzizi II I VI 1 u39 3 I y I I h 0 Correlation between CO2 levels and temperature suggests that Q 3 me I L LN quot Ix i L f39IiINJ CO2 is a Greenhouse Gas allows incoming radiation to reach I 3953 Earth39s surface but traps heat that is re emitted from land and sea O 0 Variation in CO2 levels over hundreds of millions of years reflect plate tectonics and evolution O I V 39539 39 quot I pattern Eimilar tr CEll lexrels Respectively can observe correlation between growth and decay of continental ice sheets 39i39iIII I39r391ii39liquoti39l39ii39llEg39l mnlliIii39I in1 B3III IIquot39rEi I kl II II quot 39 III 4 I n lI L II 39f i lrgi i I in i 39 39igti39 I ii I I ii Ii 39 i 7 III I i q 39rrUwI Ii39liJ iDIgIfii Ii Jlqll k s 1 1iilwMI H I1Ii iI39Ii39 i39I1 iiI 3 a iI39t3939I II 153Jl39i39l II 2 II39 iI39I II 39 IIHJITD 39i eEI II 39 1i HLi i 1 439II39QIEI39 Selim liefre piuem quot Enid glaIiaIi and IIIHIII11 intergliaciial peIiIJIIl5 if E H39FEiiEI39iIE with minimum aIIIIi maximum Large CO2 drop In mId PaeozoIc reflect evoutIon of 395I391iiquot39ii5quotrEiFLli Eiii39 woody plants increased the size of the carbon reservoir on land Development of woody plants also led to development of new mechanism for removing carbon burial of plant material on land gt peat gt coal FOOD CHAIN 0 Food Webs trace movement of carbon through communities 0 Food Chain linear transfer of carbon from one organism to another 0 Trophic Levels similar sets of producers and consumers in which energy flows UP from one level to the next 0 Trophic Pyramids diagrams showing amount of energy available at each level to feed the next one 0 Laws of Thermodynamics o 1 Energy is conserved neither created or destroyed o 2quot There is a spontaneous tendency towards increased disorder entropy 0 Energy transfer up trophic levels is inefficient o Majority of energy is lost as heat only 10 moves up T Errliaryr lEIl15IlIllIquotIElT i llnules Secnruzltary Dzzrrlsvulrner ilfl joules Primanr Ennsumer il lEl llrzmllles A Wastes and dead organisms A Bacteria furrgli arncl certair1 Secondary and tertiary Consumers olbtaln their carbon by eating primary consumers Prlimrary COHlSLlllquotlquotIE39llTS or grazers obtain thetr carlzaorr by eating prlrriary produvcersl Primary producers plants alglare and phrotosyntl ettc bacteria glenerarte organic rnolleculesr by photosynthesis animals corisurne wastes and dead organisms making their carbon and other rrutriernts available once 1 more to primary producers 0 Due to inefficient energy transfer amount of biomass of one trophic level is only 1015 of level below BACTERIA Prolkargrotio oell ELrltar3ro39l39llo cell organirzatlion or39ganization Eurkarrya Arolwaea l arorte riia riguruu5 S CU l39lC S Prokaryotes are a paraphyletic group have more similar genetic b J391r VrZI39 39 Mill u 2il1 Ia in F I39quot1 ii39Iil l 39r 0 Primary difference between prokaryotes and eukaryotes is that eukaryotes have no nuclear membrane 0 Prokaryotic cell wall made from peptidoglycan complex polymer of sugars and amino acids 0 Depending on thickness of wall can soak up more or less of stain I Grampositive soak up more stain so have a thicker cell wall 0 Includes organisms that can cause disease streptococcus or cure it streptomycetes secrete compounds that kill other bacteria and fungi in area concentration to acquire gases and nutrients O o Small cells have high surface area to volume ratio Bacteria use diffusion random motion of molecules with net movement from high concentration to low In order to get nutrients cells have to be close to environment so diffusion limits cell size Bacterial shapes o Coccoidal spherical rod helical fruiting bodies aggregation of individual cells O Thiromargerita namibiensis larger than normal bacteria but middle contains a large vacuole so still uses diffusion Proteobacteria are the most diverse bacteria Diversity of Cyanobacteria photoautotrophs capable of oxygenic photosynthesis o Single cells colonies of bound cells filaments that are coenocytic have multiple nuclei in one large cell l39quot Kl 39Ir39IrILii39 by 39rIl39l39quotl39li39l39irlI3llJl39 5 w l R If 937 quotRE 392i2ea3939 clcuiinzuu DIquotlJ39IvEr39aaquot S lI39 39Ig1 EiaI uIii 39pFrIJiI39i tle391lrlmr In i 39Ei3911j 1I392quotI DWI IimalI 1 Iasrm tJ 1LII1s in I1ll39 l lDl C39 ll l rll3939Fi39rrl 1 l Iilel Ig1 illllLlFiE1EI Ilw rccirii it cell W1 quots39El39Il39I39 ZIi i UN IEi39BE 1I3939I thi iilh39quotn39lI ll1l l39i E nhrl e39F i laicLrI up j a 1 f i39fl il 1 CI ll In izraiwsdtittuon DEM is Ir11s 2rL liJlquotlF391I izl rli r 39Ir39I 1 rl39ii IlIquotilquot tilw l39 39u iirII5t Bacterial gene diversity is a result of methods of Horizontal Gene Transfer 0 Aerobic utilizes oxygen and therefore lives in oxygenated environment 0 Anaerobic does not utilize oxygen so can live in a non oxygenated environment Eriarw IEE 0 Many bacteria respire through Fermentation 1 Huiatemph 0 autotrophs fix their own carbon 0 Most bacteria are chemoheterotrophs Carilir1 iIHnE lrIH11n39gLIri39 rmmm an anaerobic process that converts sugars to acids gasses or alcohols 0 Microbial Mats densely packed communities of mostly bacteria and archaeons that thrive where animals and seaweed can39t grow Anywhere from a few mm to cm thick Vertical gradients of abiotic factors Light penetrates deeper than 02 More anaerobic gt increases H2S causes bacteria to smell bad OOO at Q Pi 05 9 r W53 C KD E 2D g 59 C go he 59 at at ga3939 E E i 39 lt9 Q D 339 Uxmenic i iierulriiii g p m respiration 0 2 0 E Q Ehermhy rEE1iI39a1fDI1El39iI 9 fEfIllllE IZEIIiEll1 9 H D 0 Many previously undiscovered bacterial groups exist in seawater rare biosphere o Highly diverse up to 20000 types in 1L of water 510 million different microbes SULFUR CYCLE Cirganii E iiJ iJl39 0 Sulfur is important for amino acids and proteins one of A d1F39I Equotquot g T the 6 major nutrients that you need to survive A i r G 0 Cycle dominated by bacteria and archaeons EPiE1sLiI39I E 39ll w 1 FJ lquotEll p p aiziieriia J Fiiieaduicrtlxon 3 39 Ai iii39lEEE39TEIhlE respiration Aerobic respiration iEnarmr El1 iJtlrl li i iquotI 393 39lI lE39iTl39l739lE i39Tl39lIl lsIEl39lfCll3 Eiarrmiiia 5 F39liritii5irnhI39ii lziiziiztersizi 39liiliquotirii39iEiri gas quot 5 quot NITROGEN CYCLE 0 Nitrogen Fixation process of converting N2 into biologically useful 0 on n ii in s es prrit inaiHtin 7 fillitiriii rerii form ammonia NH3 l F ial n g 7 i H T g39Ari3939iiliiiviIiuirigA i N 0 Nitrification completed by chemoautotrophic bacteria mm 39339 i ii i y 7 r s 0 denitrification amp nitrogen fixation anaerobic 0 y i i T k Earst rla am 0 N M2 fimhm 0 nitrification aerobic tdim eaiimijlii ids air you breathe is 80 nitrogen but NOT biologically available if I lililii39quoti liEi Hua can t be utilized by organisms 0 fixation only occurs in specialized cells in bacteria o completed by symbiotic heterotrophic bacteria in root nodules of plants such as peanuts soybeans and alfalfa o by cyanobacteria heterotrophic bacteria and archaea in microbial mats ARCHAEA 0 first distinguished from other prokaryotes Table 251 Principal Differences among i 391irihaea Elacteria anil Eulraiya Cell containsa nucleus and other membrane bound ND ND W5 0 3 major divisions Crenarchaeota Drganalm Euryarchaeota Thaumarchaeota DNA occurs in a circular form res fes No o Euryarachaeota division includes Rquot3quotquot539 39 E E3 T95 5 3 E h h h Membrane lipids ester linked No es fes met anogemc arc aea39 met ane Photosynthesis with chlorophyll No es fes pr0d UCi n8 Capable of growth at temperatures greater than 3 quotC Yes Yes No Q Thaumarchaeota may be most Histone proteins present in cell res No quotes D t39 DNA iquot quotiquot N abundant cells in the ocean Peru prE5Equot 39quot E5 E5 D lntrons present in most genes No No fes I 3am energy by 0X39d39Zmg Capable of methanogenesis res No No NH3 Sensitive to the antibiotics chloramphenicol kanamycin ND E5 ND h t hl and streptomycin arc aea are ex remap I es Capable of nitrogen xation res fes No 0 thermophilic heat 0Ving Capable of chemoautotrophy res res No 0 hyperthermophilic very heat Table Eiilltar3iote DNA is linear Tarchaea membrane lipids are ether inleil loving live in up to 122C I thought to be ancestor of all living things halophilic salt loving acidophilic acid loving many live in deepsea hydrothermal vents MICROBES 0 Stromatolites layered structures that record sediment accumulation by microbial communities o Layers of microbes sediment microbes sediment etc o Provide a history of microbial communities and an early record of life on Earth o Evidence that life existed 35 billion years ago 0 Prokaryotes have coevolved with eukaryotes ie when one evolved then so did the other o Wolbachia parasite in insects alters the hosts reproductivity causes eggs to grow into females without fertilization I Parasite inhibits infection by viruses that cause malaria and dengue fever I By making insects resistant to diseases also benefits humans since humans usually get these diseases as a result of insect bites 0 Bioremediation bacteria are used to help clean up oilspills 0 Wastewater Treatment bacterial communities help remove nitrogen and clean up water 0 Bacteria can be found all over our body
Are you sure you want to buy this material for
You're already Subscribed!
Looks like you've already subscribed to StudySoup, you won't need to purchase another subscription to get this material. To access this material simply click 'View Full Document'