Cystic fibrosis is an autosomal recessive mutation. Mary

Last updated: 7/8/2022

Cystic fibrosis is an autosomal recessive mutation. Mary (c/c) who has cystic fibrosis is married to Jim (C/c) who has a normal phenotype. Mary and Jim have two children, the first child has cystic fibrosis (c/c), and the second child is unaffected (C/c). What is the probability that their third child will be a carrier (heterozygous) for the mutation that causes the disease?