SAT Subject Biology Practice Question 187: Answer and Explanation
17. This can result in stabilizing selection in a population.
A. Founder effect
B. Heterozygote advantage
C. Population bottleneck
D. Random mating
E. Reproductive isolation
Correct Answer: B
Heterozygote advantage confers a fitness advantage on heterozygous individuals. The amount of variance for the phenotype will decrease, though the mean will stay the same. On a graph of frequency vs. phenotype, this is depicted as a narrowing of the curve.