In Humans, Sickle-Cell Disease Is Due to a Defect in a Single

Multiple Choice

In humans, sickle-cell disease is due to a defect in a single gene and is inherited in an autosomal recessive manner. If 2 people without sickle-cell disease have a daughter who has this disease, what is the probability that their next child will be a boy with sickle-cell disease?

A) 1/16
B) 1/8
C) 1/4
D) 3/8
E) 1/2