Question

Read the article and use the information to answer the following questions.

Cystic Fibrosis

Cystic fibrosis is genetic, meaning it can be passed from parent to child. What type of mutation causes cystic fibrosis?

somatic mutation

germline mutation

silent mutation
If both parents are carriers of the defective CF gene, what is the chance that their child will have cystic fibrosis?

0%

25%

50%

100%

Answer 1

1) Germline mutation — CF is caused by inherited mutations in the CFTR gene (present in the parents' gametes).

2) 25% — if both parents are carriers (heterozygotes), each child has a 1 in 4 chance of being affected (autosomal recessive inheritance).