Cystic fibrosis is a recessive disorder. If a couple, each of whom is heterozygous for the CFTR mutation, have children, what is the probability that they will have a child with cystic fibrosis?
A) 0 percent
B) 25 percent
C) 50 percent
D) 75 percent
E) 100 percent

Question

Quizplus · Accepted Answer

When both parents are heterozygous for a recessive disorder like cystic fibrosis, there is a 25% chance for each child to inherit two copies of the mutated gene (one from each parent), resulting in the child having cystic fibrosis.

Cystic Fibrosis Is a Recessive Disorder