Question

Even though sickle cell anemia can be a lethal disease, it persists because __________.

it can only be inherited from one parent

there is a vaccine to treat it

it is a dominant disease

individuals with one allele for sickle cell anemia are resistant to malaria

Answer 1

Even though sickle cell anemia can be a lethal disease, it persists because **individuals with one allele for sickle cell anemia are resistant to malaria**.

This phenomenon is an example of balanced polymorphism, where the heterozygous condition (having one normal allele and one sickle cell allele) provides a survival advantage in malaria-endemic regions, thus maintaining the allele in the population despite its harmful effects in the homozygous condition (when an individual has two sickle cell alleles).