The answer to the first question is E so after crossing two
The answer to the first question is E, so after crossing two heterozygous parents, I thought the answer to the next problem would be 1/4, but it is 1/8. How is it 1/8? thank you
In domestic chickens, a plumage pattern called cock feathering is a sex-limited autosomal recessive trait in males. Two birds heterozygous for cock feathering are mated. What are the phenotypes of the parents? A) Male with hen feathering, female with cock feathering B) Male with cock feathering, female with cock feathering C Cannot be determined from the information given D) Male with cock feathering, female with hen feathering E) Male with hen feathering, female with hen feathering Using the same cross as in the previous problem, what fraction of the total offspring is expected to exhibit cock feathering? A) 1/4 B) 0 C 3/4 D) 1/8 E) 1/2Solution
It is given that the cock feathering is an autosomal recessive trait in males, but does not include females.
As both the parents are heterozygous, the probability of offspring with the recessive genotype is 1/4.
The fraction of offspring expected to exhibit cock feathering = probability of being a male* probability of being autosomal recessive = 1/2*1/4 = 1/8
Thus, the correct option is D). 1/8
