Sickle cell anemia is often lethal in childhood, yet the gene for sickle cell hemoglobin persists in the human population. Which statement BEST describes why this is the case?
A) Individuals with sickle cell anemia are healthier than are normal individuals.
B) Individuals with sickle cell trait can carry more oxygen in their blood than do normal individuals.
C) Individuals with normal hemoglobin have malaria infections less often than do individuals with sickle cell trait.
D) Individuals with sickle cell trait are protected from malaria infection, while normal individuals are not.
E) Individuals with sickle cell anemia have more hemoglobin in their blood than do normal individuals.

Question

Quizplus · Accepted Answer

The presence of the sickle cell gene provides some protection against malaria infection, which is prevalent in regions where sickle cell anemia is common. Individuals with sickle cell trait are less likely to develop severe malaria infections, while individuals with normal hemoglobin are not protected. Therefore, the gene for sickle cell hemoglobin persists in the population despite the risk of sickle cell anemia.

Sickle Cell Anemia Is Often Lethal in Childhood, Yet the Gene