Homozygotes with two sickle-cell alleles are selected against because of mortality. However, heterozygotes for sickle-cell allele experience little effects of sickle allele and are more likely to survive malaria. The net effect of this exposure produced evolutionary change in areas where malaria is endemic by ________.a. causing sickle-cell alleleb. distortion of red blood cellsc. increasing sickle-cell allele frequencyd. increasing the number of infected mosquitoes

Homozygotes are defined as the person who possesses two similar alleles(genes acquired from both the parents) that leads them to have a particular trait in them. While heterozygotes are illustrated as the individual having two distinct genes or alleles that leads them to possess varying traits.

As per the question, the net influence of this subjection in Malaria endemic areas is by 'increasing sickle-cell allele frequency' as it would assist in providing resistance against such diseases. Sickle-cell trait aids to offer a shielding benefit against the diseases like Malaria. Thus, option C is the correct answer.