試題詳解

3.A disease is caused by homozygosity for the g allele (G is the corresponding wild-type allele). However, the penetrance of the disease is 75%. Two individuals known to be heterozygotes have a child. What is the probability that the child exhibits the disease?
(A) 3/16
(B) 1/8
(C) 3/4
(D) 9/16
(E) 1/4