Harmful dominant alleles, like those for the huntingtin gene, are not common because in most cases
A) the brain does not make very many of them.
B) the carrier can only pass on the allele to another dominant carrier.
C) the body tends to suppress the action of dominant genes until adulthood.
D) the carrier does not survive long enough to pass on the allele via reproduction.

Question

Quizplus · Accepted Answer

Harmful dominant alleles are not common because carriers usually do not survive long enough to pass on the allele via reproduction. For example, in the case of the huntingtin gene, carriers typically develop symptoms of Huntington's disease in midlife, after they have already had children. This limits the spread of the allele through the population.

Harmful Dominant Alleles, Like Those for the Huntingtin Gene, Are