BIO 152-- FINAL EXAM!WELL DONE 2024.

Which of the following is not an observation or inference on which natural selection is based? a. There is heritable variation among individuals. b. Poorly adapted individuals never produce offspring. c. Species produce more offspring than the environment can support. d. Individuals whose characteristics are best suited to the environment generally leave more offspring than those whose characteristics are less well suited. e. Only a fraction of an individual's offspring may survive. - ANSWERSb. Poorly adapted individuals never produce offspring. Which of the following observations helped Darwin shape his concept of descent with modification? a. Species diversity declines farther from the equator. b. Fewer species live on islands than on the nearest continents. c. Birds can be found on islands located farther from the mainland than the birds' maximum nonstop flight distance. d. South American temperate plants are more similar to the tropical plants of South America than to the temperate plants of Europe. e. Earthquakes reshape life by causing mass extinctions. - ANSWERSc. Birds can be found on islands located farther from the mainland than the birds' maximum nonstop flight distance. Within six months of effectively using methicillin to treat S. aureus infections in a community, all new infections were caused by MRSA. How can this result best be explained? a. S. aureus can resist vaccines. b. A patient must have become infected with MRSA from another community. c. In response to the drug, S. aureus began making drug-resistant versions of the protein targeted by the drug. d. Some drug-resistant bacteria were present at the start of treatment, and natural selection increased their frequency. e. The drug caused the S. aureus DNA to change. - ANSWERSb. A patient must have become infected with MRSA from another community. The upper forelimbs of humans and bats have fairly similar skeletal structures, whereas the corresponding bones in whales have very different shapes and proportions. However, genetic data suggests that all three kinds of organisms diverged from a common ancestor at about the same time. Which of the following is the most likely explanation for these data? a. Humans and bats evolved by natural selection, and whales evolved by Lamarckian mechanisms. b. Forelimb evolution was adaptive in people and bats, but not in whales. c. Natural selection in an aquatic environment resulted in significant changes to whale forelimb anatomy. d. Genes mutate faster in whales than in humans or bats. e. Whales are not properly classified as mammals. - ANSWERSc. Natural selection in an aquatic environment resulted in significant changes to whale forelimb anatomy. DNA sequences in many human genes are very similar to the sequences of corresponding genes in chimpanzees. The most likely explanation for this result is that a. humans and chimpanzees share a relatively recent common ancestor. b. humans evolved from chimpanzees. c. chimpanzees evolved from humans. d. convergent evolution led to the DNA similarities. e. humans and chimpanzees are not closely related. - ANSWERSd. convergent evolution led to the DNA similarities. Natural selection changes allele frequencies because some ____ survive and reproduce more successfully than others. a. alleles b. loci c. gene pools d. species e. individuals - ANSWERSe. individuals No two people are genetically identical, except for identical twins. The main source of genetic variation among human individuals is a. new mutations that occurred in the preceding generation. b. genetic drift due to the small size of the population. c. the reshuffling of alleles in sexual reproduction. d. geographic variation within the population. e. environmental effects. - ANSWERSc. the reshuffling of alleles in sexual reproduction. Sparrows with average-sized wings survive severe storms better than those with longer or shorter wings, illustrating a. the bottleneck effect b. disruptive selection c. frequency-dependent selection d. neutral variation e. stabilizing selection - ANSWERSe. stabilizing selection There are 40 individuals in population 1, all with genotype A1A1, and there are 25 individuals in population 2, all with genotype A2A2. Assume that these populations are located far from each other and that their environmental conditions are very similar. Based on the information given here, the observed genetic variation is most likely an example of a. genetic drift b. gene flow c. disruptive selection d. discrete variation e. directional selection - ANSWERSa. genetic drift A fruit fly population has a gene with two alleles, A1 and A2. Tests show that 70% of the gametes produced in the population contain the A1 allele. If the population is in Hardy-Weinberg equilibrium, what proportion of the flies carry both A1 and A2? a. 0.7 b. 0.49