General Biology II Mock Exam Test 2
1. In a Hardy-Weinberg population with two alleles, A and a, that are in equilibrium, the
frequency of allele a is 0.1. What is the frequency of individuals with AA genotype?
a. 0.20
b. 0.32
c. 0.42
d. 0.81
2. Approximately 1 out of every 2,500 Caucasians in the United States is born with the
recessive disease cystic fibrosis. According to the Hardy-Weinberg equilibrium equation,
approximately what percentage of people are carriers?
a. about .08%
b. about 2%
c. about 4%
d. about 10%
e. about 96%
ANS: If q2 equals 1/2,500, then q equals .02, p equals .98, and 2pq equals approximately .04, or
4%.
3. Assume a population in Hardy-Weinberg equilibrium for a character trait with these
genotypic frequencies: AA = 0.25, Aa = 0.50, and aa = 0.25. If you remove all the
homozygous dominants and allow the remaining population to reproduce (again under
Hardy-Weinberg conditions), what will be the frequency of homozygous dominants in the
next generation?
a. 0
b. 0.11
c. 0.22
d. 0.44
e. 0.50
4. 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. 2%
B. 4%
C. 8%
D. 16%
E. 32%
5. Which of the following sets of conditions is required for Hardy-Weinberg equilibrium?
, a. a large population, random mutations, and no migration of alleles in or out of the
population
b. a large population, no mutations, with natural selection
c. no mutations, no natural selection, with sexual selection
d. random mating, no natural selection, and a large population
6. Although each of the following has a better chance of influencing gene frequencies in
small populations than in large populations, which one most consistently requires a small
population as a precondition for its occurrence?
a. mutation
b. nonrandom mating
c. genetic drift
d. natural selection
7. Evolution
A. must happen, due to organisms' innate desire to survive
B. must happen whenever a population is not well adapted to its environment
C. can happen whenever any of the conditions for Hardy-Weinberg equilibrium are not
met.
D. requires the operation of natural selection
8. Over time, the movement of people on Earth has steadily increased. This has altered the
course of human evolution by increasing
a. nonrandom mating
b. geographic isolation
c. genetic drift
d. gene flow
9. Which of the following is most likely to produce an African butterfly species in the wild
whose members have one of two strikingly different color patterns?
A. artificial selection
B. directional selection
C. stabilizing selection
D. disruptive selection
10. _____ and _____ generate variation, whereas _____ results in an adaptation to the
environment.
A. Genetic drift … natural selection … mutation
1. In a Hardy-Weinberg population with two alleles, A and a, that are in equilibrium, the
frequency of allele a is 0.1. What is the frequency of individuals with AA genotype?
a. 0.20
b. 0.32
c. 0.42
d. 0.81
2. Approximately 1 out of every 2,500 Caucasians in the United States is born with the
recessive disease cystic fibrosis. According to the Hardy-Weinberg equilibrium equation,
approximately what percentage of people are carriers?
a. about .08%
b. about 2%
c. about 4%
d. about 10%
e. about 96%
ANS: If q2 equals 1/2,500, then q equals .02, p equals .98, and 2pq equals approximately .04, or
4%.
3. Assume a population in Hardy-Weinberg equilibrium for a character trait with these
genotypic frequencies: AA = 0.25, Aa = 0.50, and aa = 0.25. If you remove all the
homozygous dominants and allow the remaining population to reproduce (again under
Hardy-Weinberg conditions), what will be the frequency of homozygous dominants in the
next generation?
a. 0
b. 0.11
c. 0.22
d. 0.44
e. 0.50
4. 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. 2%
B. 4%
C. 8%
D. 16%
E. 32%
5. Which of the following sets of conditions is required for Hardy-Weinberg equilibrium?
, a. a large population, random mutations, and no migration of alleles in or out of the
population
b. a large population, no mutations, with natural selection
c. no mutations, no natural selection, with sexual selection
d. random mating, no natural selection, and a large population
6. Although each of the following has a better chance of influencing gene frequencies in
small populations than in large populations, which one most consistently requires a small
population as a precondition for its occurrence?
a. mutation
b. nonrandom mating
c. genetic drift
d. natural selection
7. Evolution
A. must happen, due to organisms' innate desire to survive
B. must happen whenever a population is not well adapted to its environment
C. can happen whenever any of the conditions for Hardy-Weinberg equilibrium are not
met.
D. requires the operation of natural selection
8. Over time, the movement of people on Earth has steadily increased. This has altered the
course of human evolution by increasing
a. nonrandom mating
b. geographic isolation
c. genetic drift
d. gene flow
9. Which of the following is most likely to produce an African butterfly species in the wild
whose members have one of two strikingly different color patterns?
A. artificial selection
B. directional selection
C. stabilizing selection
D. disruptive selection
10. _____ and _____ generate variation, whereas _____ results in an adaptation to the
environment.
A. Genetic drift … natural selection … mutation
