In domestic chickens, some males display a plumage pattern called cock feathering. Other males and all females display a pattern called hen feathering. Cock feathering is an autosomal recessive trait that is exhibited in males only.
- Two heterozygous birds are mated. What fraction of the total offspring is expected to exhibit cock feathering?
A) 0
B) 1/8
C) 1/4
D) 1/2
E) 3/4

Question

Quizplus · Accepted Answer

Cock feathering is autosomal recessive and sex-limited to males. From two heterozygous birds (Hh x Hh), 1/4 of the offspring will be homozygous recessive (hh), but only males (1/2 of the offspring) can express the trait, so 1/4 * 1/2 = 1/8 of the total offspring will exhibit cock feathering.

In Domestic Chickens, Some Males Display a Plumage Pattern Called