Sickle-cell disease is an autosomal recessive disorder that causes the red blood cells of an affected person to be rigid and abnormally shaped. The life expectancy of a person affected by the disorder is approximately 45 years. Carriers of the disease produce some sickled cells, but not enough to be symptomatic.Malaria is a potentially fatal disease caused by the protist Plasmodium falciparum.Studies have shown that those affected by sickle-cell disease (genotype ss), as well as carriers who possess only one sickle-cell allele (Ss), are much more resistant to malaria than those with homozygous dominant genotypes (SS). This resistance is created in part by the rupturing of any sickled red blood cells that are infected with the parasite, preventing Plasmodium falciparum from reproducing and making it more susceptible to the host's immune system.Which of the following statements best predicts what would happen in response to a prolonged epidemic of malaria in a population with no previous exposure to malaria?    A.  The frequency of the homozygous recessive genotype (ss) would decrease.  B.  The frequency of the dominant allele (S) would increase.  C.  The frequency of the sickle-cell allele (s) would increase.  D.  The frequency of the homozygous dominant genotype (SS) would increase.

Sickle-cell disease is an autosomal recessive disorder that causes the red blood cells of an affected person to be rigid and abnormally shaped. The life expectancy of a person affected by the disorder is approximately 45 years. Carriers of the disease produce some sickled cells, but not enough to be symptomatic.

Malaria is a potentially fatal disease caused by the protist Plasmodium falciparum.

Studies have shown that those affected by sickle-cell disease (genotype ss), as well as carriers who possess only one sickle-cell allele (Ss), are much more resistant to malaria than those with homozygous dominant genotypes (SS). This resistance is created in part by the rupturing of any sickled red blood cells that are infected with the parasite, preventing Plasmodium falciparum from reproducing and making it more susceptible to the host's immune system.

Which of the following statements best predicts what would happen in response to a prolonged epidemic of malaria in a population with no previous exposure to malaria?