Ian and Bryony are both carriers for two autosomal recessive disorders,PKU (chromosome 12)and cystic fibrosis (chromosome 7).They are expecting a daughter.What is the probability that she will have PKU but not CF?
A)9/16
B)3/16
C)1/2
D)1/16

Question

Quizplus · Accepted Answer

The probability of the daughter inheriting PKU is 1/4 (since both parents are carriers), and the probability of not inheriting CF is 3/4 (since both parents are carriers). The disorders are on different chromosomes, so the probabilities are independent. Multiply the probabilities: 1/4 * 3/4 = 3/16.

Ian and Bryony Are Both Carriers for Two Autosomal Recessive