Download Unit 6 Review Answers - Iowa State University

Unit 6 Review
Supplemental Instruction
Iowa State University
Leader:
Course:
Instructor:
Date:
Chelsey
BIO 211 (3)
Colbert
Monday 11/28/11
1. In Darwin’s view of descent with modification _____.
a. An organism’s traits only affect its own survival
b. Natural selection can improve the match between an organism and its environment
c. Individuals can evolve
d. Environmental changes have no effect on the organisms living in that environment
2. The smallest unit that can evolve in a(n) _____.
a. Species
b. Genotype
c. Individual
d. Population
3. Vestigial organs are _____.
a. Remnants of structures that were useful to an organism’s ancestors
b. One piece of evidence that does not support the theory of evolution
c. Examples of anatomical imperfections such as the human knee
d. Homologies that can only be observed in embryos
4. To describe evolution as a “scientific theory” means that _____.
a. It is not factual
b. It is a matter of opinion
c. It is a broad model that is supported by many observations and much experimental
evidence
d. It is considered law
5. In the context of populations, how do we define evolution?
a. Evolution is a change in a population’s allelic frequencies over generations
b. Evolution is the tendency for some individuals in a populations to leave more offspring
than others
c. Evolution is the way in which sexual reproduction can rapidly spread advantageous traits
throughout the population
d. Evolution is always caused by natural selection
6. In the Hardy-Weinberg equation, p2 represents _____.
a. The total alleles in the gene pool
b. The frequency of heterozygous dominant individuals in the population
c. The frequency of homozygous recessive individuals in the population
d. The expected frequency of homozygous dominant individuals in the population
7. In a large population of bonobos, the frequency of the recessive allele is initially 0.1. What is the
frequency of the dominant allele? Assume that there are two alleles of this gene.
a. 10%
b. 20%
c. 50%
d. 90%
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8. In a population in Hardy-Weinberg equilibrium, 1% of the individuals in a population show the
recessive trait of a certain characteristic. In this situation, what is the value of p?
a. 99%
b. 0.81
c. 0.9
d. 0.18
9. In a certain group of African people, 4% are born with sickle-cell disease (homozygous
recessive). If this group is in Hardy-Weinberg equilibrium, what percentage of the group has the
selective advantage of being more resistant to malaria (heterozygous) than those individuals who
are homozygous for normal hemoglobin or for sickle-cell disease?
a. 4%
b. 8%
c. 16%
d. 32%
10. Which of the following sets of conditions is required for Hardy-Weinberg equilibrium?
a. A large population, no mutations, and natural selection
b. A large population, random mutations, and no migrations of alleles in or out
c. No mutations, sexual selection, and no natural selection
d. Random mating, no natural selection, and a large population
11. A population of 15 birds inhabits a fairly new island. Ten of the birds are dark brown and five of
them are light brown. By chance, two of the dark brown birds and three of the light brown birds
die before producing any offspring. All of the birds in the next generation are dark brown. This
change in phenotypic frequency can be attributed to _____.
a. Natural selection
b. Genetic drift
c. Gene flow
d. Disruptive selection
12. An earthquake hits a small island. All but a small group of closely related lizards are eliminated,
and the survivors spread out over the island. This is an instance of _____.
a. Founder effect
b. Bottleneck effect
c. Gene flow
d. Nonrandom mating
13. Which of the following is the best example of gene flow?
a. A small population of humans colonizes a newly formed island
b. An earthquake results in the formation of a canyon, splitting a population of toads apart
c. Wind blows pollen from one population of plants to another and cross-fertilization occurs
d. All the mutations in a population were neutral
14. A population of squirrels is preyed upon by small hawks. The smaller squirrels can escape into
burrows. The larger squirrels can fight off the hawks. After several generations, the squirrels in
the area tend to be very small or very large. What process is responsible for this outcome?
a. Stabilizing selection
b. Directional selection
c. Disruptive selection
d. Balancing selection