In regions where malaria is prevalent, individuals who are _____ have a selective advantage.
A)heterozygous for the S (sickling)allele
B)homozygous for the S (sickling)allele
C)homozygous for the A (nonmutant)allele
D)None of the answer options is correct.

Question

Quizplus · Accepted Answer

Individuals who are heterozygous for the S (sickling) allele have a selective advantage in regions where malaria is prevalent. This is because individuals homozygous for the S allele have sickle cell anemia, a serious disease that can be fatal. However, individuals who are heterozygous for the S allele have some protection against malaria because the abnormal hemoglobin in their red blood cells can make it more difficult for the malaria parasite to survive. Therefore, these individuals have a better chance of surviving to reproduce and pass on their genes, giving them a selective advantage in regions where malaria is prevalent. Homozygotes for the A (nonmutant) allele do not have any protection against malaria.

In Regions Where Malaria Is Prevalent, Individuals Who Are _____