bio final practice 2021

Which of the following statements is FALSE about positive selection? A. It decreases heterozygosity B. It can be a result of domestication C. It decreases polymorphism D. It removes mutations You are studying a population of flowers with a colour polymorphism. Wild-type homozygotes have purple flowers, heterozygotes have pink flowers, and recessive homozygotes have white flowers. You notice a very high frequency of pink flowers in this population. What explanation would be MOST consistent with these observations? A. There are high amounts of inbreeding B. There is strong negative selection on the flower color locus C. There is a heterozygote advantage D. This is evidence for a recent bottleneck You and your labmate are performing a selection experiment on a population of mice. You make sure to only breed the mice with the shortest tails. After 5 generations, average tail length in the population has decreased. When you stop the experiment, after a few generations, average tail length increases. Why might this be? A. Having short tails is deleterious once artificial selection is removed B. There is very little variation in the population C. There is inbreeding depression within this population D. Tail length is a continuous trait Which of the following statements is TRUE about neutral theory? A. It can only be applied to certain organisms, such as insects B. It was developed by Richard Lewontin C. It maintains that the polymorphic loci we actually observe do not affect survival or reproduction D. It lacks the ability to identify heterozygotes www.oxdia.com DownloaderID 46616 ItemID 25463 www.oxdia.com Downloader ID: 46616 Item ID: 25463 Item ID: 25463 Downloader ID: 46616

You and your best friend are studying a newly discovered plant species. What clues would tell you that it is outcrossing? i) Low proportion of deleterious mutations in the genome ii) Small flowers iii) High genetic diversity iv) Male and female gametes produced at the same time A. i and iii B. ii and iv C. i, iii and iv D. i, ii, iii and iv Fill in the blanks in the following sentence: Asexual reproducers contribute ___ copies of their genes to the next generation compared to sexually reproducing individuals because ___ A. Half as many; asexuals can fertilize themselves after meiosis and pass on all their genes B. Twice as many; asexuals can fertilize themselves after meiosis and pass on all their genes C. Half as many; meiosis does not occur, therefore all of the asexuals’ genetic material is passed on D. Twice as many; meiosis does not occur, therefore all of the asexuals’ genetic material is passed on Asexually reproducing species tend to: A. Be located on the tips of phylogenetic trees B. Be located at the root of phylogenetic trees C. Be placed anywhere in a phylogeny D. Be extinct Which of the following is the correct definition of migration: A. Migration describes the movement of genes between populations B. Migration describes the movement of individuals between populations C. Migration describes the movement of species between geographic ranges D. Migration describes BOTH the movement of genes between populations AND the movement of individuals between populations www.oxdia.com DownloaderID 46616 ItemID 25463 www.oxdia.com Item ID: 25463 Downloader ID: 46616 Downloader ID: 46616

You and your friend cannot agree whether two groups of asexually-reproducing rotifers are distinct species. Which of the following species concepts would be MOST useful for settling this argument? i) Phylogenetic species concept ii) Biological species concept iii) Taxonomic species concept A. i and ii B. ii and iii C. i and iii D. iii only Two closely-related finch species occasionally form hybrids. These hybrids tend to have beaks of an intermediate size to their parental species, which have large and small beaks respectively. What evidence would suggest there is extrinsic postmating isolation? A. The hybrids die early due to deleterious gene combinations B. The hybrids cannot reproduce with other hybrids C. The hybrids cannot reproduce with members of either parent species D. The hybrids are not able to obtain enough food due to beak size Which of the following statements is TRUE about allopolyploidy? A. Allopolyploids usually have poor fitness B. Allopolyploidy can result in sympatric speciation C. Allopolyploids are produced by two individuals of the same species D. Autopolyploidy is more common than allopolyploidy Which of the following statements is FALSE about the above phylogeny? A. ABC is a monophyletic group B. BCDE is a paraphyletic group C. DE is a monophyletic group D. DE is a paraphlyletic group www.oxdia.com DownloaderID 46616 ItemID 25463 www.oxdia.com

Which of the following is TRUE about the above phylogeny? i) Taxon A has the ancestral state of Character x ii) The common ancestor to Taxa D+E evolved the derived state of Character z iii) Taxa A, B and C have the ancestral state of Character y A. i and ii B. i only C. iii only D. ii only You and your friend are arguing whether reptiles (lizards, snakes, tuataras, turtles, crocodiles) are a paraphyletic group. You are convinced it is paraphyletic, your friend is not. Why are you correct? A. It is paraphyletic because your friend did not include an ancestral tetrapod in this group B. It is paraphyletic because birds share a common ancestor with reptiles and are closely related to crocodilians C. It is paraphyletic because turtles and crocodiles are too morphologically distinct D. It is paraphyletic because reptiles and amphibians share a common ancestor How does a meiotic drive locus “cheat” Mendel’s laws? A. It cheats the law of segregation by preventing recombination B. It cheats the law of segregation by favouring transmission of a particular allele C. It cheats the law of independent assortment by inducing epistasis D. It cheats the law of independent assortment by increasing recombination Selfing, asexuality, and segregation distortion appear to provide short-term evolutionary advantages. What reason below can explain why we do not see complete selfing, asexuality, and segregation distortion? A. Developmental plasticity B. Countervailing selection at another level of biological organization C. Genetic drift D. Balancing selection www.oxdia.com DownloaderID 46616 ItemID 25463 www.oxdia.com Downloader ID: 46616 Item ID: 25463 Item ID: 25463 Downloader ID: 46616 Item ID: 25463 Downloader ID: 46616 Item ID: 25463 Item ID: 25463 Item ID: 25463 Downloader ID: 46616 Item ID: 25463

Based on the tree shown below, which of the following statements is FALSE? A. There is one homoplasious character. B. Only Taxa B and C have the ancestral state of Character 7. C. The group of Taxa B+C is the sister group to the group of Taxa G+A+F+E. D. Taxon A is more closely related to Taxon E than Taxon G is related to Taxon E. A researcher wants to compare the antennae length of paired (mating) males to unpaired (unmated) males of a fly species. Over 7 days, she samples males from the mating swarm. Every time she catches a paired male she immediately catches an unpaired male from the same mating swarm. She then measures the antenna length of every male she catches. Below is data she collected from one night of sampling. Which of the following statements is FALSE? Paired males (mm) Unpaired males (mm) 2.3 1.5 1.9 0.8 2.6 1.7 2.1 1.8 2.1 0.7 1.8 1.2 2.2 1.4 2.4 0.9 2.0 1.6 2.5 1.3 A. The paired males have a greater range than the unpaired males. B. The mode of the paired males is 2.1 mm. C. A t-test should be used to see if there is a significant difference in antenna length between paired and unpaired males. D. Male antennae length is a continuous trait. www.oxdia.com DownloaderID 46616 ItemID 25463 www.oxdia.com Downloader ID: 46616 Item ID: 25463 Downloader ID: 46616 Downloader ID: 46616 Item ID: 25463 Downloader ID: 46616

In your own words, describe one genetic cost of sexual reproduction discussed in lecture, being sure to explain why this cost is associated with sexual reproduction (compared to asexual reproduction). 1 point for describing the cost and 1 point for explaining why this cost is associated with sexual reproduction. Below are the genetic costs discussed in lecture: Ɣ 50% less genetic transmission/two-fold cost to meiosis : sexual reproduction is defined by having undergone reductive division to produce haploid gamete (gamete with half the chromosome number of parent) which fuses with another gamete so only transmitting 50% of genes to next generation, whereas in asexual reproduction 100% genes are transmitted to next generation Ɣ Break up of adaptive genes combinations : asexual reproduction transmits allele combination to next generation but sexual reproduction breaks up allele combinations through meiosis and recombination Ɣ Cost of producing males : asexual females produce twice as many males as sexual females without needing them for reproduction. Hence, why make males You are convinced you have identified a key innovation. What are two pieces of evidence that can be used to support this interpretation? 1 point for each: Ɣ the feature/trait is associated with increased species richness/adaptive radiation Ɣ this diversification is observed in replicate sister group comparisons Note : Stating “Individuals with the trait can use new resources or live in new habitats” can earn 0.5 point You are a conservation biologist working on a captive breeding program for a black-footed ferrets. You have the budget to establish either two populations of 100 ferrets each, or 10 populations of 20 ferrets each. Which approach do you think is most likely to succeed, and why? 1 point for stating 2 populations of 100 ferrets 1 point for explaining why: greater genetic diversity, greater heterozygosity/less homozygosity, reduced chances of inbreeding depression, better ability to adapt www.oxdia.com DownloaderID 46616 ItemID 25463 www.oxdia.com