Question 14

(Multiple Choice)

Duchenne muscular dystrophy is a serious condition caused by a recessive allele of a gene on the human X chromosome. The patients' muscles weaken over time because they have a lack or decreased levels of dystrophin, a muscle protein. Which of the following correctly predicts the probability of muscular dystrophy in female children?


A) Females can never have this condition.
B) One-fourth of the daughters of an affected man would have this condition.
C) One-half of the daughters of an affected man and a carrier woman would have this condition.
D) One-half of the daughters of an unaffected man and a carrier woman would have this condition.

Answer