Why are dominant, yet harmful, alleles like the huntingtin gene so rare in our genomes?
A) Only a few harmful alleles affect the nervous system.
B) The carrier does not survive long enough to pass on the allele.
C) The alleles for disorders are not active until adulthood.
D) The allele can be transmitted only to another dominant carrier.

Question

Quizplus · Accepted Answer

Dominant, harmful alleles like the huntingtin gene are rare in our genomes because carriers usually do not survive long enough to pass on the allele. Most people who carry the allele die before reproducing due to the onset of the disease at an adult age. This reduces the frequency of the allele in the population over time.

Why Are Dominant, Yet Harmful, Alleles Like the Huntingtin Gene