In Areas of Africa in Which Malaria Is Prevalent, Many

Multiple Choice

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