Question

what will happen to the frequency of the recessive allele for the hbs gene when there is an outbreak of malaria?
the frequency will increase.
the frequency will decrease.
the frequency will remain constant.
it is impossible to predict how the allele frequency will change.
the frequency will be cut in half with each generation.

Explanation:

The HbS gene's recessive allele (associated with sickle - cell trait) has a survival advantage in malaria - prone environments. Heterozygotes (with one HbS allele) are more resistant to malaria. During a malaria outbreak, individuals with the recessive HbS allele (especially heterozygotes) have higher survival and reproductive rates. This leads to an increase in the frequency of the recessive HbS allele in the population as natural selection favors those with the allele in the presence of malaria.

Answer:

A. The frequency will increase.