BSC 108 Exam 3
University of Alabama
1. Which of the following best describes natural selection?
A) Changes in an individual’s traits to adapt to the environment
B) The survival and reproduction of individuals best suited to their environment
C) Random changes in population genetics
D) Traits developed during an organism’s lifetime are passed on to offspring
Answer: B) The survival and reproduction of individuals best suited to their
environment
2. What is the ultimate source of genetic variation in a population?
A) Sexual reproduction
B) Natural selection
C) Mutations
D) Genetic drift
Answer: C) Mutations
3. Which of the following is NOT a mechanism of evolution?
A) Natural selection
B) Gene flow
C) Genetic drift
D) Mitosis
,Answer: D) Mitosis
4. If two heterozygous individuals for a trait (Aa x Aa) are crossed, what is the
expected genotype ratio?
A) 1:2:1
B) 3:1
C) 2:1:1
D) 1:1
Answer: A) 1:2:1
5. Which type of selection favors individuals with extreme phenotypes?
A) Stabilizing selection
B) Disruptive selection
C) Directional selection
D) Balancing selection
Answer: B) Disruptive selection
6. A population is in Hardy-Weinberg equilibrium. If p = 0.7, what is q?
A) 0.3
B) 0.49
C) 0.5
D) 0.21
Answer: A) 0.3
7. Which type of symbiotic relationship benefits one organism while harming the
other?
A) Mutualism
B) Commensalism
, C) Parasitism
D) Competition
Answer: C) Parasitism
8. The greenhouse effect is primarily caused by the buildup of which gas?
A) Oxygen
B) Nitrogen
C) Carbon dioxide
D) Hydrogen
Answer: C) Carbon dioxide
9. Which of the following is an example of a vestigial structure?
A) Bird wings used for flight
B) Whale pelvic bones
C) Shark teeth
D) Insect antennae
Answer: B) Whale pelvic bones
10. Which process results in the formation of gametes?
A) Mitosis
B) Binary fission
C) Meiosis
D) Fertilization
Answer: C) Meiosis
True or False
11. Genetic drift has a greater effect on large populations than on small populations.
University of Alabama
1. Which of the following best describes natural selection?
A) Changes in an individual’s traits to adapt to the environment
B) The survival and reproduction of individuals best suited to their environment
C) Random changes in population genetics
D) Traits developed during an organism’s lifetime are passed on to offspring
Answer: B) The survival and reproduction of individuals best suited to their
environment
2. What is the ultimate source of genetic variation in a population?
A) Sexual reproduction
B) Natural selection
C) Mutations
D) Genetic drift
Answer: C) Mutations
3. Which of the following is NOT a mechanism of evolution?
A) Natural selection
B) Gene flow
C) Genetic drift
D) Mitosis
,Answer: D) Mitosis
4. If two heterozygous individuals for a trait (Aa x Aa) are crossed, what is the
expected genotype ratio?
A) 1:2:1
B) 3:1
C) 2:1:1
D) 1:1
Answer: A) 1:2:1
5. Which type of selection favors individuals with extreme phenotypes?
A) Stabilizing selection
B) Disruptive selection
C) Directional selection
D) Balancing selection
Answer: B) Disruptive selection
6. A population is in Hardy-Weinberg equilibrium. If p = 0.7, what is q?
A) 0.3
B) 0.49
C) 0.5
D) 0.21
Answer: A) 0.3
7. Which type of symbiotic relationship benefits one organism while harming the
other?
A) Mutualism
B) Commensalism
, C) Parasitism
D) Competition
Answer: C) Parasitism
8. The greenhouse effect is primarily caused by the buildup of which gas?
A) Oxygen
B) Nitrogen
C) Carbon dioxide
D) Hydrogen
Answer: C) Carbon dioxide
9. Which of the following is an example of a vestigial structure?
A) Bird wings used for flight
B) Whale pelvic bones
C) Shark teeth
D) Insect antennae
Answer: B) Whale pelvic bones
10. Which process results in the formation of gametes?
A) Mitosis
B) Binary fission
C) Meiosis
D) Fertilization
Answer: C) Meiosis
True or False
11. Genetic drift has a greater effect on large populations than on small populations.
