Dorset sheep have horns in both sexes while Suffolk sheep ha

Dorset sheep have horns in both sexes while Suffolk sheep have no horns in either sex. When Dorset and suffolk sheep are crossed to each other, the male offspring all have horns while the female offsrping have no horns. Which of the following could explain this pattern of inheritance?

A.) Incomplete dominance

B.) Incomplete penetrance

C.) Sex limited inheritance

D.) Sex influenced inheritance

I know that the answer is D, but why?

Solution

Answer:

D.) Sex influenced inheritance

The traits are autosomal and their expression is controlled by sex hormones. So it is called sex-influenced inheritance. At least one allele of a gene can express the trait in males by the influence of androgens whereas two alleles are required to express in females.