Why are relatively few inherited disorders caused by dominant alleles?
A) Most disorders caused by dominant alleles lead to sterility, which means the dominant allele will not be passed on.
B) Genetic testing can more readily identify dominant rather than recessive alleles; genetic counseling has more successfully reduced the incidence of disorders caused by dominant alleles.
C) Every person with one of the dominant alleles will have the disorder, and people with most of these disorders do not usually live long enough to reproduce, so the allele will not be passed on.
D) Individuals carrying dominant alleles for a disorder are less likely to actually have the disorder than are individuals carrying a recessive allele for a disorder.

Question

Quizplus · Accepted Answer

Most disorders caused by dominant alleles are fully penetrant, which means every person with one of the dominant alleles will have the disorder. Many of these disorders are severe and reduce the life span of affected individuals, so they are less likely to reproduce and pass on the allele to the next generation.

Why Are Relatively Few Inherited Disorders Caused by Dominant Alleles