The Persistence of the Sickle-Cell Anemia Allele in Some African

Question

The persistence of the sickle-cell anemia allele in some African populations is the result of ____.  
A) a high rate of mutation of the normal allele to the sickle-cell anemia allele
B) the advantage conferred by the heterozygous form when malaria is prevalent
C) nonrandom mating
D) a decline in the occurrence of malaria in Africa
E) genetic drift

Accepted Answer

The sickle-cell anemia allele confers an advantage in heterozygous individuals when malaria is prevalent, as it provides some resistance to the disease. Therefore, individuals carrying the sickle-cell allele have a higher chance of surviving and passing on their genes, resulting in the persistence of the allele in some African populations.