BIS2B Midterm2 KEY, Fall 2008

BIS2B Midterm2 KEY, Fall 2008 - Biological Sciences 23...

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Unformatted text preview: Biological Sciences 23 Instructors: Strong and Patricelli Fall Quarter 2008 Midterm #2 Please Read the Instructions First. o Check your pages--there are’pages in this exam (including this page & the gripe sheet). - You are responsible for making sure that you have all the pages. - This examination is worth 80 points. o Please bubble in the 9 digits of your student ID number on your scantron. Bubble the number from the bottom of the scantron into the scantron number box. Mark Test Form A. Calculators CAN be used on the test. Multiple Choice Questions—20 questions worth 2 pts. each: 40 points total o Indicate your answers on the scantron sheet using a number 2 or a test scoring pencil. Press heavily, don’t stray out of the margins and completely erase any changed answers. Choose only ONE answer per question - If you think that a multiple choice question is ambiguous or confusing, use the “explanation sheet” at the end of the examination to explain the problem. Put your name on this sheet—we tear them off to read them! Fill-in Questions: 4 questions, each with multiple partsl worth 40 points total - Use pen only (no grade corrections for pencil). 0 Write only one answer per question--you can elaborate on an answer, but you will not be given any credit if you write multiple different answers to the question, or include unnecessary information. - Spelling rules: 1/2 credit for 2-3 letters wrong or transposed. No points will be given if the misspelling alters the meaning of the word. You have 50 minutes to complete the exam. Budget your time — be sure to leave enough time to complete the fill-ins at the end of the exam, as they are worth 50% of the exam. KEEP YOUR ANSWERS TO THE FILL-INS BRIEF - ALL CAN EASILY BE ANSWERED WITH JUST A FEW WORDS, A LINE ON A GRAPH, OR A SIMPLE PUNNETI' SQUARE. - Choose only QNE answer per question 1. Natural selection acts directly on .— All 9 F 141593 g may Change 0 V“ th 0t :5“ ———.' . to“ a; mzfggciépe “hm: fie, 'l’0 5 eo'f'lon, Lu‘l’ Scaled” c) thepopulation ale—E dhrecl’lrg on m PhWfiTfe'ec/‘fifia I ‘ r t m éd 11:15:2255; fiend ‘f’WL deb-"WWI o‘c NW TD “a. mg! 2. When a few individuals from a mainland species colonize an island, which of the following will likely be true for the island population a) there will be lower allelic diversity than in the mainland population b) there will be lower homozygosity than in the mainland population c there will be a different allele frequency than in the mainland population ¢ both (a) and (c) e) all of the above 3. Which of the following is M a condition for a population to be in Hardy—Weinberg equilibrium? a) There is random mating of individuals with respect to genotype ‘ ‘ / b) There isnogeneflow fisgumbs an (argue/t. '3 @l‘ here is a small population size ———37 H “w ‘5” l ' W Fofdlwx" '4 There is no differential survival among genotypes Sr‘z 9- e) Afl are conditions for Hardy-Weinberg equilibrium 4. Which of the following is/are example(s) of traits that evolved primarily through intrasexual selection? a Elaborate colors and behaviors used in courtship by peacocks and sage-grouse ntlers on male elk, used for fighting c) camouflaged feathers on female birds that her to avoid predators (1) Both (a) & (b) are correct e) both (a) & (c) are correct 5. Which of the following was N_OT one of the observations that lead to Darwin’s theory of evolution by natural selection a) Populations should increase exponentially if all offSpring survived to reproduce b The individual members of a species typically differ in phenotype Offspring tend to resemble parents due to inheritance of characteristics acquired by / their parents through use or disuse d) New and stable “varieties” with desirable qualities can be created by artificial Tlfis is , selection La mawolk 5 e) All of the above are observations used by Darwin in his theory of Natural Selection “W 9’01 5 S If; I w OK i g in (“red— \ 6. The Z allele is dominant and codes for blue flowers, 1 is recessive and codes for ree - Z; individual is crossed with a g individual, what will be the resulting ratio 0 phenotypes? @Half blue, half green flowers b) Half homozygotes and half heterozygotes c) All blue flowers (1) All green flowers e) Both (a) & (b) 7. Once a particular strain of influenza (flu) Virus is common in a human population, most individuals will have developed an immune response to that strain. But a rare, novel strain of the flu virus would be able to spread quickly to almost any individual. This advantage of genetic novelty causes continual evolution of new viral strains, with new versions common each year. This is best considered an example of a) Disruptive selection W AdvaKJ-q 3/; 7‘0 MR 9% My b) Stab'lizi Sel t' N E E S ,, M 1 ng ec ion ‘ S W? M c Sexual Selection Frequency-dependent Selection 6 Heterozygote Advantage (S 8. Which of the following is NOT a condition necessary for natural selection to occur The, “Eff IllW1 a Individuals must reproduce to form the next generation / Mk I ¢The earth must be billions of years old to allow time for natural selection 0 .. Fofi ~10 " ' c Individuals within a populatiou must vary in phenotype \ n 3:, "JD M d) Individuals pass on at least some of their traits to their offspring [:0 (- An MW e) Individuals with different traits have differential survival or reproductive success Ng 6- during the struggle for existence 96”) ‘ one? VA «WA, 9. With the Direct Benefits model of sexual selection, 08 a) females choose males based on sexual signals which indicate genes for health or immune-system quality, which will be passed on to their offspring b male sexual signals will likely be under disruptive selection by female choice é females choose males based on sexual signals which indicate food, territory or other benefits for the female d) Both (a) & (c) 6) Both (b) & (c) 10. Cooperative behaviors can evolve because a) they directly increase the fitness of the cooperative individual b) species with more cooperative individuals are favored by selection » x a 54 0 these behaviors are directed toward close kin 72’ g I r both(a)&(c) fame. a! $42,344 W e) homo?) &(c) may; W 900le “1a” W 0( sp 4%. 5 585", N4c‘c4 “ final/10+ Thruer Mac/fiat 5Z0 no‘l" (Lil: M 69 W SfU/ng’ SOMe 5F¢ol¢4 hut (mart a- N“ emit—raw— bchquiou 44mm 0M.) Maw; 09 (“1.16am 11. Over 3 years, you study a large population of crickets with 2 alleles, G and g, at a single fl locus that controls the color of the crickets’ legs. G is dominant to g and codes for dark legs. “‘4” ‘ \(0 The frequency of allele G is p(G) = 0.15 at the beginning of the study. At the end of the M study, the genotypic frequencies are CC = 0.18, Gg = 0.50, and gg = 0.28. You suspect that Q4 during the study period, a the population has been in Hardy-Weinberg equilibrium throughout the study (No éhere has been selection favoring individuals with dark legs c) the crickets have been mating with close relatives d) the crickets have been preferentially mating with individuals who share the same color legs as themselves 6) homozygotes have had a fitness advantage 12. Alleles of different genes assort with complete independence during gamete formation if they are on different a) genes loci chromosomes d) homozygotes e) all of the above 13. Eusociality evolved in social hymenoptera in part because a) they are haplodiploid b) females are more related to their sisters than to their own potential offspring c) br > c d individuals benefit more from indirect fitness benefits than possible direct benefits all of the above 14. Darwin and Wallace were both greatly influenced by the work of homas Malthus / go Mdl \ a.ng WM‘ “WK c) RbigegTrilvneres W “Dd/WW” n d) Hardy and Weinberg e) All of the above 15. Darwin’s ideas about blending inheritance created problems for his theory of evolution by natural selection because a) blending inheritance should increase the amount of variation in offspring, making it impossible for natural selection to operate. b) blending inheritance should reduce the amount of variation in offSpring, which should increase the rate of evolution by natural selection. 0) natural selection always reduces genetic variation, just like blending inheritance, so the two could not be distinguished. (1) natural selection always increases genetic variation, just like blending inheritance, so the two could not be distinguished. blending inheritance reduces the amount of genetic variation from generation—t0— generation, and genetically based variation is essential for evolution by natural selection to occur. 16. Quantitative traits m S 0/053 a) are typically determined by a combination of genes and the environment b) can show evolutionary change without a change in allele frequencies 0 are polygenic oth (a) & (c) e) all of the above 17. You discover a population of birds where males build nests, incubate the eggs and feed the wda hatched chicks. Which one of the following is likely for this species? W I 4 a) Females are larger and more ornamented than males +9 a“ 0 fl? J L +55 d re b) Males produce fewer, larger gametes than females 3”” (walrfr Females have sexual traits that indicate genetic benefits for the male’s offspring 2' We”? &a>&<c> . My" 6) All of the above W‘- ’H‘o?u€tr 0: (“AOL w a! 18. The skin color of an anolis lizard is controlled by 2 genes, the T gene (with 2 alleles, T and t) and the H gene (H and b). When individuals have the TThh genotype, they are red; when «Hobs they are Tthh, they are red; and when they are TtHb or TTHH, they are yellow. This I\ example demonstrates wxfi a) codominance 5’0 \ W”? ‘ b dihybridization C/ \m ‘1!" l ‘0 v . . 7 u 4 b” *0 pistaSIS h x a «V J, d) incomplete dominance \X/ Q ax W ,n L, e) pleiotropy “a” \\. O X?“ \‘ ( D 19. Which of the following is 13% about kin Selection V‘ a) The genes for cooperative behavior are passed on through the offspring of the cooperative individual @If the relatedness between 2 individuals is low, then the benefit of cooperation must be very high to the receiver and/or the cost of helping must be low c) If the relatedness between 2 individuals is high, then the benefit of cooperation must be very high to the receiver and/or the cost of helping must be low (1) Kin selection only works in haplodiploid social insects e) You would have higher fitness if you raised your first cousins than if you raised your own offspring 20. When any individual produces gametes, each gamete receives only one copy of the gene. This is an example of Crossing over Mendel’s First Law: The Law of Segregation c) Mendel’s First Law: The Law of Independent Assortment d) Mendel’s Second Law: The Law of Segregation e) Mendel’s Second Law: The Law of Independent Assortment 09 v6 \ _ b) A ?0?U LAC-n0 'J is a group of individuals of the same species that 504“ “I “Q lives & interbreeds in a particular place c) (0 I is when the same gene has multiple phenotypic effects d) The model of intersexual selection that proposes that females choose males based on arbitrary traits that give them more attractive sons is called AWA' v SEXUA’ L Sear—770A) wok.- e) A random change in one base pair of DNA that causes a different amino acid to be used 55x in protein production is called a EN M UTA-DQN 50 N 7; I“ ODEL M914 tun/e. (‘Jul'i' b31151 words “((vNAwAY" 4:0" wrl‘f" .. 0’ .. (pun-l. C“ Says“) 117 garCH’ W W 3. You use genetic techniques to genotype a population of African wild dogs at a locus controlling spotting pattern which has 2 alleles, D and (1. You find 120 DD individuals, 8 Dd individuals and 72 dd individuals. a) What are the observed genotype frequencies for this population? 7]): I26 -.gl 374: 72:00:36 I :: %aa:'09 zoo ‘ b) The frequency of the D allele in this population is 0 6 2' 0) Given the allele frequencies you calculated in part (b) above, what would be the Hardy-Weinberg equilibrium expectation for genotype frequencies in the next generation for this population? (note: if you do not know how to calculate allele frequencies for part (b), then for partial credit, use f(D)=0. 55 to answer parts (6), (d) i & (e). Clearly indicate that this is what you ’re doing!) ?=.62. ~ ~ 7977‘?“ 38W» 94:93:34”, 644 75.1%». m Momma Move. (a) 7% 444122. [Mrflqi 05m are- film» ‘0 T o I. p“ u; N < T393; 5mm form, 50 M repaid“ 3" 5 h t A tar w ab Item, d) You use genetic techniques to measure genotype frequencies in the next generation, and you find that they are the same as those you previously observed (calculated in part (a)). Do you think that the population is in Hardy-Weinberg equilibrium? Briefly explain your answer (I sentence). . I/n‘¢ CIDSQ’V‘A gimo+2 ¢, 0&0 "'1 we a not maid/L 9'fo / 41“” a _ . . hc-iflo 23 9944 Wu qcfui-CX . M m M 3’ $ e) Based on your answers above, name onetype of process that may have been acting on this population. Briefly explain your answer (I sentence). em 7. chedS {NBReEZDiNé’ ‘ls likJJISMQ W 44"— —::»M: q; hui-uozjgam q/IMM @bszfl exp .H a #14153“ U ' K we; “Tm/{LL 0R Vosrer A~$SORTATN€ MATING— (‘9 17°17" “a 31“" w. ease, are. .k we w M We [24 e a 7— ?g a; (23:1. ifé‘aig w: Selection or Disrupti [Diversifying Selection, a) draw the fitness function and the response function (show the parental and ofi‘spring generation on the response function); label all the axes on our lots and label the relevant curves as “ arental” and “offs rin ”. 0M1 on? 01; BELOW-n What type of selection are you representing below? g‘TABlLIZ—iNGr ’ergcnoflg "DKRQ-PT-we J J: M" \J FIT‘N El”; 0 a 1: :‘L O :FfiWEKY {same ‘5‘ W“? . ' Q 2 0 eve What kind of change would there be in the mean for the offspring population under this selective regime? (increased, decreased or no change) 1\ (D / - e" F1 0?“ VE : Swmuuqar , no A -) Dimmer/Al, ' ‘ - ' or {x I “mice: “ Mattsz ab'w— M. A c) What kind of change would there be in the variance for the offspring population under this selective regime? (increased, decreased or no changflh WWW = Acme _ Q6 r‘ ‘° - o 00“ )(W a“ J A” l.‘ Q at w W M" W?) so «043‘ W e to“? 2. You w0uld like to cross 2 strains of fruit flies, to learn more about 2 traits of interest, head * \(V‘ (1) color (the B-locus) and wing shape (the W—locus). At the head color locus, the B allele V7“ V140" (black head) is dominant to the b—allele (brown head). At the wing shape locus, the W or! allele (normal wings) is dominant to the E allele (shriveled wings). You erform the followin dih brid cross between two fruit flies each of which is hetero ous for both genes (genotype: BbWE). a) Draw a Punnett square showing the possible genotypes. Boo LW ’39), (920, M MS "WE? MAY D W 30° 9300“) (Bka @360“)! Blame: 4M A TIA/“010:0” “' “Fl-[ATLS PINE to) wa lilo W60 BBQ/2°, 125002 age 5an you CAN7EU “r. (T's A CAWTAL 6 Moon (gm {BBWflgBégog by“) m towel arse V 9 T‘» ‘ \ 1393 Emmy L,th £91.03 lain/w 5/,“Cr‘a, (Pym C b) What is the expected ratio of phenotypes for this cross? (be sure to name the Phenotypes you’re referring to) I , ,. Cb“; ta .. t‘ (affix athakiai/wmemjg state Aux/s r. c My 5! ’5 brole lie-J /nal‘m4-Z 1 l anhqll/thiwla —->/v\osT Moe $33: I WHO (“3% “flaw”! 799'“ = q/Ié=%e‘3/Ic=%t aimin- ‘Be ape/r1: (Ni-th PH/ENOT‘IPES C-‘° mum C4-C4} ngtK c at IS e probability of getting a BbWW offspring? ...
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BIS2B Midterm2 KEY, Fall 2008 - Biological Sciences 23...

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