The mutation that became the recessive characteristic for sickle-cell anemia is adaptive in:
A) malaria-prevalent environments
B) non-African Americans only
C) African Americans
D) no known environments and, as a recessive characteristic, is likely to die out

Question

Quizplus · Accepted Answer

The mutation that causes sickle-cell anemia is adaptive in malaria-prevalent environments because having one copy of the mutated gene makes an individual less susceptible to malaria. However, having two copies of the mutated gene (homozygous) causes sickle-cell anemia. This is why sickle-cell anemia is more common in African American populations, where malaria has historically been prevalent. The option D is incorrect since sickle cell anemia is still commonly found in many areas around the world, including sub-Saharan Africa, India, and the Middle East.

The Mutation That Became the Recessive Characteristic for Sickle-Cell Anemia