Biol 345 Exam 2 ASU Questions and Answers
Which locus is most likely to be in linkage disequilibrium with the mutation (all else
being equal; assume a sexually reproducing organism)? - Answer-The one closest to
the star
/.Which of these provides the selection pressure maintaining sexual reproduction,
according to the Red Queen hypothesis? - Answer-Pathogens of the sexual organism
evolve to overcome the organism's defenses.
/.What is the best explanation for the observation that
eukaryotes that seem superficially simple can have much larger genomes (in terms of
mass or number of base pairs) than organisms that have complex
anatomy, structure, or behavior? - Answer-Some organisms have a tremendous amount
of noncoding DNA, like repetitive sequences.
/.Which mechanism for the appearance of a new gene in a species' genome could also
explain different phylogenetic tree topologies when using different genes? - Answer-
Horizontal gene transfer
/.Which event will not alter an organism's karyotype? - Answer-Sequence inversion
/.Human eyes have a very different morphology from that of fly eyes. If Pax6 sequence
and function is highly conserved, how can one explain morphological divergence in
eyes and their ectopic expression in these flies? - Answer-Both genes turn on eye
development, but different genes are regulated by them in different species.
/.Imagine a scenario in which several lakes have been
colonized by marine-origin sticklebacks. In each lake, body armor disappears over time.
Which change most likely caused this? - Answer-Independent, unique mutations
occurred in each population that rendered enhancers in the armor pathway useless,
which were then favored by natural selection.
/.Which observation is inconsistent with Haeckel's idea that "ontogeny recapitulates
phylogeny"? - Answer-The pharyngeal clefts and branchial
arches of embryonic mammals and reptiles never acquire the form seen in adult fish.
/.What is metagenomics? - Answer-sequencing DNA from a group of species from the
same ecosystem
/.Most examples of polyploidy speciation involve _______. - Answer-Plants
/.You collect individuals from different allopatric populations of a leaf-eating beetle. In
the laboratory, you conduct mate-choice experiments to assess levels of reproductive
isolation among beetles from different populations. Assuming that ecological speciation
, occurred in the wild, which pattern should you expect? - Answer-Less reproductive
isolation among populations that share similar habitats
/.Which observation does not provide evidence that sexual selection can be an
important cause of speciation? - Answer-In many species, recombination rates differ for
males and females.
/.Which of the following is a case of altruism? - Answer-A prairie dog gives up a foraging
opportunity to keep watch for predators.
/.Individual amoebae of the slime mold Dictyostelium discoideum aggregate to form a
spore-producing fruiting body. Cheaters make spores, but do not contribute to the stalk.
Since many more spores with cheating genotypes are dispersed, they
have higher fitness. Why does directional selection not lead to fixation of the cheater
genotype? - Answer-This is actually a case of frequency-dependent selection. With too
many cheaters in a population, the fruiting body's stalk is not built well, and all
individuals have lower fitness.
/.When food supplies are limited, individual amoebae of the slime mold Dictyostelium
discoideum aggregate to form a multicellular "slug." Which of the following statements
about the conflict between individual and group benefit in this species is true? - Answer-
Cheater" mutations occur, increasing individual fitness at the expense of the group.
/.Suppose five boats are adrift at sea, each one containing a number of your relatives,
and you have the power to save one boat from a dire fate. According to kin selection
theory, it would be in the best interest of your genome to save a boat that contains? -
Answer-one sister, one half-brother, and three cousins.
/.Which of these is a "spiteful action"? - Answer-A student turns in a classmate for
cheating and as evidence admits to having cheated himself.
/.Which of the following is most likely to favor the evolution of highly virulent parasites? -
Answer-Transmission between unrelated members of the population (horizontal
transmission)
/.A woman has a son with her first partner, and that son has a son of his own—the
grandchild of the original woman. The original woman also has a son with a
second partner, who also grows up to have another son; a second grandchild. What is
the relatedness, r, of the two grandchildren? - Answer-0.0625
/.Coevolution in predator-prey interactions does
not lead to? - Answer-ecological character displacement.
/.The Red Queen hypothesis is often used to explain what? - Answer-coevolution in
parasite-host interactions.
Which locus is most likely to be in linkage disequilibrium with the mutation (all else
being equal; assume a sexually reproducing organism)? - Answer-The one closest to
the star
/.Which of these provides the selection pressure maintaining sexual reproduction,
according to the Red Queen hypothesis? - Answer-Pathogens of the sexual organism
evolve to overcome the organism's defenses.
/.What is the best explanation for the observation that
eukaryotes that seem superficially simple can have much larger genomes (in terms of
mass or number of base pairs) than organisms that have complex
anatomy, structure, or behavior? - Answer-Some organisms have a tremendous amount
of noncoding DNA, like repetitive sequences.
/.Which mechanism for the appearance of a new gene in a species' genome could also
explain different phylogenetic tree topologies when using different genes? - Answer-
Horizontal gene transfer
/.Which event will not alter an organism's karyotype? - Answer-Sequence inversion
/.Human eyes have a very different morphology from that of fly eyes. If Pax6 sequence
and function is highly conserved, how can one explain morphological divergence in
eyes and their ectopic expression in these flies? - Answer-Both genes turn on eye
development, but different genes are regulated by them in different species.
/.Imagine a scenario in which several lakes have been
colonized by marine-origin sticklebacks. In each lake, body armor disappears over time.
Which change most likely caused this? - Answer-Independent, unique mutations
occurred in each population that rendered enhancers in the armor pathway useless,
which were then favored by natural selection.
/.Which observation is inconsistent with Haeckel's idea that "ontogeny recapitulates
phylogeny"? - Answer-The pharyngeal clefts and branchial
arches of embryonic mammals and reptiles never acquire the form seen in adult fish.
/.What is metagenomics? - Answer-sequencing DNA from a group of species from the
same ecosystem
/.Most examples of polyploidy speciation involve _______. - Answer-Plants
/.You collect individuals from different allopatric populations of a leaf-eating beetle. In
the laboratory, you conduct mate-choice experiments to assess levels of reproductive
isolation among beetles from different populations. Assuming that ecological speciation
, occurred in the wild, which pattern should you expect? - Answer-Less reproductive
isolation among populations that share similar habitats
/.Which observation does not provide evidence that sexual selection can be an
important cause of speciation? - Answer-In many species, recombination rates differ for
males and females.
/.Which of the following is a case of altruism? - Answer-A prairie dog gives up a foraging
opportunity to keep watch for predators.
/.Individual amoebae of the slime mold Dictyostelium discoideum aggregate to form a
spore-producing fruiting body. Cheaters make spores, but do not contribute to the stalk.
Since many more spores with cheating genotypes are dispersed, they
have higher fitness. Why does directional selection not lead to fixation of the cheater
genotype? - Answer-This is actually a case of frequency-dependent selection. With too
many cheaters in a population, the fruiting body's stalk is not built well, and all
individuals have lower fitness.
/.When food supplies are limited, individual amoebae of the slime mold Dictyostelium
discoideum aggregate to form a multicellular "slug." Which of the following statements
about the conflict between individual and group benefit in this species is true? - Answer-
Cheater" mutations occur, increasing individual fitness at the expense of the group.
/.Suppose five boats are adrift at sea, each one containing a number of your relatives,
and you have the power to save one boat from a dire fate. According to kin selection
theory, it would be in the best interest of your genome to save a boat that contains? -
Answer-one sister, one half-brother, and three cousins.
/.Which of these is a "spiteful action"? - Answer-A student turns in a classmate for
cheating and as evidence admits to having cheated himself.
/.Which of the following is most likely to favor the evolution of highly virulent parasites? -
Answer-Transmission between unrelated members of the population (horizontal
transmission)
/.A woman has a son with her first partner, and that son has a son of his own—the
grandchild of the original woman. The original woman also has a son with a
second partner, who also grows up to have another son; a second grandchild. What is
the relatedness, r, of the two grandchildren? - Answer-0.0625
/.Coevolution in predator-prey interactions does
not lead to? - Answer-ecological character displacement.
/.The Red Queen hypothesis is often used to explain what? - Answer-coevolution in
parasite-host interactions.
