BIO 107 EXAM QUESTIONS AND
ANSWERS LATEST UPDATE
1. To be considered homologous, two organs must be...
A. exact copies of each other within the same individual organism.
B. almost completely identical in structure and function across different species.
C. similar in structure as a result of shared ancestry.
D. similar in function, but may have totally different structures in different species. -
Answer-C
2. Which of these traits is most important to an individual's evolutionary fitness?
A. Having many offspring that survive to reproductive age
B. Ability to defeat other individuals when fighting over food or territory
C. Effective camouflage that protects against predators
D. Intelligence and the ability to learn from experience - Answer-a
3. Cheetahs nearly became extinct but recovery efforts managed to save them. Now,
most cheetahs are genetically identical. This is due to:
A. natural selection
B. the bottleneck effect during genetic drift
C. random mating
D. selective migration - Answer-B
4. Which phrase best describes natural selection?
a. The differential survival and reproduction of individuals
b. Chance variations in traits
c. The processes that lead individuals to resemble their parents
d. The potential for all species to increase rapidly in number - Answer-A
5. Biologists recently discovered that black wolves got their coat color from exchanging
genes with dogs. This is an example of
a. genetic drift.
b. gene pools.
c. gene flow.
d. a founder effect. - Answer-C
6. Different populations of mice that were previously isolated now experience gene flow.
What is the most likely outcome after several generations?
, a. The populations will become more genetically similar to one another.
b. The populations will become less genetically similar to one another.
c. The total amount of genetic variation across all of the populations will increase.
d. The total amount of genetic variation across all of the populations will decrease. -
Answer-C
7. Suppose mutation and selection no longer occurred in a small, isolated population of
nematodes. Which process would most likely continue operating, and what would be the
most likely effect on the extent of genetic variation?
a. Gene flow would lead to an increase in genetic variation.
b. Gene flow would lead to a decrease in genetic variation.
c. Genetic drift would lead to an increase in genetic variation.
d. Genetic drift would lead to a decrease in genetic variation. - Answer-D
8. Polydactyly (having more than five fingers on a hand) is much more common in some
isolated human populations than it is elsewhere. This is most likely an example of a(n)
_______, which is due to the evolutionary mechanism called _______.
a. founder effect; gene flow
b. founder effect; genetic drift
c. adaptation; gene flow
d. genetic ratchet; gene flow - Answer-B
9. In a population of sawflies, 20 percent of the population is homozygous for allele A
and 45 percent is homozygous for allele a. Assuming that A and a are the only alleles at
this locus, what percent of the population is heterozygous?
a. 10 percent
b. 20 percent
c. 35 percent
d. 45 percent - Answer-c
10. A sparrow population currently eats seeds that are mostly of medium size. Which
condition will most likely lead to more directional selection?
a. A decrease in population size of the sparrow
b. More seeds that are either considerably smaller or considerably larger than average,
with fewer of intermediate size
c. More seeds that are intermediate in size
d. More seeds that are somewhat larger than average and fewer that are smaller than
average - Answer-d
11. Disruptive selection for body size would most likely occur when
a. there is heterozygote advantage.
b. predators prefer to consume larger individuals.
c. small individuals are more likely to become desiccated.
d. intermediate-sized individuals are less able to find a food source. - Answer-D
12. Which statement about fitness and natural selection is true?
ANSWERS LATEST UPDATE
1. To be considered homologous, two organs must be...
A. exact copies of each other within the same individual organism.
B. almost completely identical in structure and function across different species.
C. similar in structure as a result of shared ancestry.
D. similar in function, but may have totally different structures in different species. -
Answer-C
2. Which of these traits is most important to an individual's evolutionary fitness?
A. Having many offspring that survive to reproductive age
B. Ability to defeat other individuals when fighting over food or territory
C. Effective camouflage that protects against predators
D. Intelligence and the ability to learn from experience - Answer-a
3. Cheetahs nearly became extinct but recovery efforts managed to save them. Now,
most cheetahs are genetically identical. This is due to:
A. natural selection
B. the bottleneck effect during genetic drift
C. random mating
D. selective migration - Answer-B
4. Which phrase best describes natural selection?
a. The differential survival and reproduction of individuals
b. Chance variations in traits
c. The processes that lead individuals to resemble their parents
d. The potential for all species to increase rapidly in number - Answer-A
5. Biologists recently discovered that black wolves got their coat color from exchanging
genes with dogs. This is an example of
a. genetic drift.
b. gene pools.
c. gene flow.
d. a founder effect. - Answer-C
6. Different populations of mice that were previously isolated now experience gene flow.
What is the most likely outcome after several generations?
, a. The populations will become more genetically similar to one another.
b. The populations will become less genetically similar to one another.
c. The total amount of genetic variation across all of the populations will increase.
d. The total amount of genetic variation across all of the populations will decrease. -
Answer-C
7. Suppose mutation and selection no longer occurred in a small, isolated population of
nematodes. Which process would most likely continue operating, and what would be the
most likely effect on the extent of genetic variation?
a. Gene flow would lead to an increase in genetic variation.
b. Gene flow would lead to a decrease in genetic variation.
c. Genetic drift would lead to an increase in genetic variation.
d. Genetic drift would lead to a decrease in genetic variation. - Answer-D
8. Polydactyly (having more than five fingers on a hand) is much more common in some
isolated human populations than it is elsewhere. This is most likely an example of a(n)
_______, which is due to the evolutionary mechanism called _______.
a. founder effect; gene flow
b. founder effect; genetic drift
c. adaptation; gene flow
d. genetic ratchet; gene flow - Answer-B
9. In a population of sawflies, 20 percent of the population is homozygous for allele A
and 45 percent is homozygous for allele a. Assuming that A and a are the only alleles at
this locus, what percent of the population is heterozygous?
a. 10 percent
b. 20 percent
c. 35 percent
d. 45 percent - Answer-c
10. A sparrow population currently eats seeds that are mostly of medium size. Which
condition will most likely lead to more directional selection?
a. A decrease in population size of the sparrow
b. More seeds that are either considerably smaller or considerably larger than average,
with fewer of intermediate size
c. More seeds that are intermediate in size
d. More seeds that are somewhat larger than average and fewer that are smaller than
average - Answer-d
11. Disruptive selection for body size would most likely occur when
a. there is heterozygote advantage.
b. predators prefer to consume larger individuals.
c. small individuals are more likely to become desiccated.
d. intermediate-sized individuals are less able to find a food source. - Answer-D
12. Which statement about fitness and natural selection is true?
