In areas of Africa in which malaria is prevalent, many human populations exist in which the allele that produces sickle-cell disease and the allele for normal red blood cells occur at constant frequencies, despite the fact that sickle-cell disease frequently causes death at an early age. This phenomenon is an example of
A) the founder effect.
B) a stable polymorphism.
C) mutation.
D) nonrandom mating.
E) Both b and c

Question

Quizplus · Accepted Answer

A stable polymorphism refers to the occurrence of two or more alleles at relatively constant frequencies over multiple generations, which is seen in this case with the sickle-cell allele and normal red blood cell allele. The fact that this polymorphism is maintained suggests that there may be some advantage to having the sickle-cell allele in areas where malaria is prevalent.

In Areas of Africa in Which Malaria Is Prevalent, Many