Question

If we denote a cystic fibrosis gene with a c and a​ disease-free gene with a C​ (since the disease is​ recessive), then only a cc person will actually have the disease. Such persons would ordinarily die before parenting​ children, but a child can also inherit the disease from two Cc parents​ (who themselves are healthy—that ​is, have no symptoms but are​ "carriers" of the​ disease). Suppose a child is born to one cystic fibrosis carrier parent and one​ non-carrier parent. Find the probability that that the child will be a carrier.

Answer 1

With a simple punnett square we see that there is a 50% chance the child will be a carrier.