Question

A child has hypertrichosis, but neither parent has excessive body hair. Is hypertrichosis inherited as a dominant mutation or recessive?

a) Dominant
b) Recessive
c) Co-dominant
d) Polygenic

Answer 1

Hypertrichosis is inherited as a recessive trait, and so it will be observed in individuals that are homozygous for the recessive allele.

Step-by-step explanation:

Hypertrichosis is a condition with excessive body hair growth. In the scenario where a child has hypertrichosis but neither parent displays this trait, the condition could be due to a recessive allele.

It is possible for the parents to be heterozygous carriers of the recessive gene without showing the phenotype.

The child, having inherited two copies of the recessive allele (one from each parent), would then express the recessive phenotype of hypertrichosis.

This pattern of inheritance, where an individual must have two copies of the recessive allele to express the trait, is known as autosomal recessive inheritance. Therefore, the correct answer to the question 'Is hypertrichosis inherited as a dominant mutation or recessive?' is b) Recessive.

A recessive trait will be observed in homozygous individuals for that trait. Hence, the correct response to the question 'A recessive trait will be observed in individuals that are for that trait.' is c) homozygous.