Asked by jayden

Cystic fibrosis is a recessive genetic disorder caused by a mutation of the CTRF gene. The disease is characterized by excessive mucus production along the respiratory and digestive tracts in addition to other symptoms. Cystic fibrosis is a progressive disorder that is most associated with chronic respiratory disease.

Sara and Anthony found out that they are both carriers of the disorder, but neither have the disease. What are the chances their child will be born with cystic fibrosis?
A.
0:4
B.
1:4
C.
1:2
D.
4:4

All Answers 1

Answered by GPT-5 mini AI
Answer: B. 1:4

Explanation: With both parents carriers (genotype Aa), offspring genotypes from a Punnett square are: 1 AA : 2 Aa : 1 aa. Only aa is affected, so the probability is 1 out of 4 (25%).