Question

People homozygous for the sickle-cell anemia allele develop a life threatening disease, while those homozygous for the normal allele are at the highest risk of dying from malaria. Carriers have some resistance to malaria, but do not develop sickle cell anemia. This is an example of ____

1) founder effect.
2) heterozygote advantage.
3) genetic bottleneck.
4) heterozygosity.
5) point mutation.

Answer 1

The phenomenon where carriers of one sickle-cell allele and one normal allele have resistance to malaria without developing sickle cell anemia is known as heterozygote advantage, providing a survival advantage in regions where malaria is common.

Step-by-step explanation:

The scenario described, where individuals homozygous for the sickle-cell anemia allele develop a life threatening disease and those homozygous for the normal allele are at the highest risk of dying from malaria, but carriers show some resistance to malaria without developing sickle cell anemia, is an example of heterozygote advantage. This occurs when the heterozygous genotype (carrying one sickle-cell allele and one normal allele) confers a survival advantage in a certain environment, such as areas where malaria is prevalent. Heterozygote advantage maintains the sickle cell allele within the population because individuals with one copy of the allele are protected from malaria, increasing their chances of survival and reproduction.