Question

in some human populations, the proportion of individuals who are heterozygous for the sickle cell allele is much higher than would be expected by chance alone. why?
multiple choice

• heterozygous individuals have an advantage over individuals with two normal alleles.
• individuals with two sickle cell alleles have an advantage over heterozygous individuals.
• individuals with two normal alleles have an advantage over heterozygous individuals.
• individuals with two sickle cell alleles have an advantage over individuals with two normal alleles.

Explanation:

This problem relates to the concept of heterozygote advantage in population genetics. Heterozygous individuals for the sickle cell allele (carriers) are resistant to malaria, which gives them a survival advantage over individuals with two normal alleles (who are susceptible to malaria) in regions where malaria is prevalent. This advantage leads to a higher proportion of heterozygotes in such populations than expected by chance.

Answer:

Heterozygous Individuals have an advantage over individuals with two normal alleles.