In a certain country, all children with cystic fibrosis die before reaching adulthood. For this lethal disease, the normal allele, denoted by C, is dominant to the mutant allele, denoted by c. In that...

In a certain country, all children with cystic fibrosis die before reaching adulthood. For this lethal disease, the normal allele, denoted by C, is dominant to the mutant allele, denoted by c. In that country, the probability is p that a person is only a carrier; that is, he or she is Cc. If Mr. J, a resident of the country had a brother who died of cystic fibrosis, what is the probability that Mr. J’s next child will have cystic fibrosis?