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%
B)25%
C)50%
D)75%
E)100%

Question

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%
B)25%
C)50%
D)75%
E)100%

Quizplus · Accepted Answer

In a punnett square, if both parents are heterozygous carriers for cystic fibrosis, there is a 25% chance that their child will inherit two copies of the mutated CFTR gene, resulting in cystic fibrosis. This is because each parent has a 50% chance of passing on the mutated gene to their offspring, and if both parents pass on the mutated gene, the child will have cystic fibrosis.

Cystic Fibrosis Is a Recessive Disorder