Name ______KEY_____________ Biology 112 – Quiz (Chapter 24)

Circle the letter of the one alternative that best completes the statement or answers the question.

1. (1 points) Zoos carefully coordinate the breeding of zoo animals, often sending animals from one zoo to mate with animals from another zoo. This practice allows zoos to:

A) Artificially select for preferred traits and prevent inbreeding depression.

B) Decrease mutation rates and increase gene flow.

C) Minimize genetic drift and maintain genetic diversity.

D) Increase sexual selection and prevent genetic bottlenecks.

E) All of the above answers apply.

2. (1 point) For biologists studying a large flatworm population in the lab, which Hardy-Weinberg condition is most difficult to meet?

A) no selection

B) no gene flow

C) no genetic drift

D) random mating

E) no mutation

3. (1 point) For a biologist studying a small fish population in the lab, which Hardy-Weinberg condition is easiest to meet?

A) no selection

B) no genetic drift

C) no mutation

D) random mating – either of these two is acceptable

E) no gene flow

4) (1 point) Cystic fibrosis is a genetic disorder in homozygous recessives that causes death during the teenage years. Is it likely that the cystic fibrosis gene is found in a population in Hardy-Weinberg Equalibrium?

A) Yes B. No

5. (2 points) The Dunkers are a religious group that moved from Germany to Pennsylvania in the mid-1700s. They do not marry with members outside their own immediate community. Today, the Dunkers are genetically unique and differ in gene frequencies, at many loci, from all other populations including their original homeland. Which of the following likely explains the genetic uniqueness of this population?

A) founder effect and genetic drift

B) population bottleneck and Hardy-Weinberg equilibrium

C) sexual selection and inbreeding depression

D) heterozygote advantage and stabilizing selection

E) mutation and natural selection

6. (2 points) In 1986 a nuclear power accident in Chernobyl, USSR (now Ukraine) led to high radiation levels for miles surrounding the plant. The high levels of radiation caused elevated mutation rates in the surviving organisms, and evolutionary biologists have been studying rodent populations in the Chernobyl area ever since. Based on your understanding of evolutionary mechanisms, which of the following most likely occurred in the rodent populations following the accident?

A) Mutation caused the fixation of new alleles.

B) Mutation caused genetic drift and decreased fitness.

C) Mutation by itself led to major changes in rodent physiology over time.

D) Mutation led to increased genetic variation and a higher rate of evolutionary change.

7. (2 points) Genetic drift occurs in a population. Which of the following statements might be true?

A) The population was relatively small.

B) Genetic drift increased the population's fitness.

C) Genetic drift decreased the population's fitness.

D) Two of the above statements might be true.

E) Any of the above statements might be true. Partial credit for any other answer