Question

the recessive allele for sickle cell anemia is more prevalent in regions of africa where malaria is prevalent, than it is in regions where there is no malaria. this is due to
multiple choice
heterozygous advantage.
frequency dependent selection.
bottleneck effect.
founder effect.

Explanation:

Individuals heterozygous for the sickle - cell allele have some resistance to malaria. In malaria - prevalent regions, this gives them a survival and reproductive advantage over those without the allele, increasing the frequency of the sickle - cell allele. This is an example of heterozygous advantage. Frequency - dependent selection is related to the fitness of a phenotype depending on its frequency in the population. The bottleneck effect occurs when a population undergoes a drastic reduction in size. The founder effect occurs when a new population is established by a small number of individuals.

Answer:

A. heterozygous advantage