An online article that your professor asked you to critique states that African Americans cannot contract malaria, even if they go to endemic areas, because of a genetic trait that confers protection from the disease. Your response is that this article is incorrect because
A. African Americans have lost the allele for normal red blood cells through genetic drift from their ancestral African population.
B. balanced polymorphism means that not all African Americans are heterozygous for the sickle cell trait.
C. protection from malaria cannot be conferred by genes.
D. African Americans are more likely to have thalassemia, which does not protect a person completely from contracting malaria.
Answer: Balanced polymorphism means that not all African Americans are heterozygous for the sickle cell trait.