Question

Carriers of cystic fibrosis have some protection against intestinal infections such as cholera. However, people with two copies of the cystic fibrosis allele develop a life-threatening disease. The mutant allele is very common in people of northern European descent because of

A. disruptive selection.
B. directional selection.
C. artificial selection.
D. sexual selection.
E. stabilizing selection.

Answer 1

Carriers of cystic fibrosis have some protection against intestinal infections such as cholera, but people with two copies of the cystic fibrosis allele develop a life-threatening disease. The mutant allele is common in people of northern European descent due to a heterozygote advantage.

Step-by-step explanation:

Carriers of cystic fibrosis have some protection against intestinal infections such as cholera, but people with two copies of the cystic fibrosis allele develop a life-threatening disease. The mutant allele is common in people of northern European descent due to a heterozygote advantage. It has been hypothesized that carriers of the cystic fibrosis mutation may have greater-than-normal resistance to certain infectious diseases.