Cystic fibrosis is an inherited autosomal recessive disease affecting the cells that produce saliva, sweat, digestive juices, and mucus. Evidence to support this particular mode of inheritance includes the fact that
A) Cystic fibrosis is more common in males than females.
B) Parents who are phenotypically normal can have an afflicted child.
C) Individuals with cystic fibrosis are all heterozygous.
D) females have a decreased chance of inherting cystic fibrosis due to the inactivation of the second X chromosome.
Answer: B) Parents who are phenotypically normal can have an afflicted child.