What is the chance of a child being a carrier of cystic fibrosis if both his mother and father are carriers?
1.100%
2.66%
3.25%
4.50%
5.0%
exp:
Cystic fibrosis is an autosomal recessive disease. There is therefore a 1 in 2 chance of a child being a carrier, 1 in 4 of being affected and 1 in 4 of being normal.