The genes for sex-linked traits are carried on either the x or y chromosome. duchenne muscular dystrophy (dmd) is a recessive, sex-linked disease that is carried on the x chromosome. a woman with dmd and a man without the disease have a child. which statement best describes the likelihood of the disease passing to their child? a. there is a 100 percent chance that their daughter will have the disease. b. there is a 50 percent chance that their son will have the disease. c. there is a 50 percent chance that their daughter will have the disease. d. there is a 100 percent chance that their son will have the disease.

There is a 50% probability that the child will be a boy. If this is the case, he will inherit the X chromosome from his mother and the Y chromosome from his father. Since the woman has DMD, the boy will certainly inherit the disease, since he only has one X chromosome and it carries the disease. We know that both of the mother's X chromosomes carry the disease because since it is recessive, both of her chromosomes must have it in order for her to have it. 

There is also a 50% probability that the child is girl. If this is the case, she will inherit a normal X chromosome from her father and the disease-carrying X chromosome from her mother. Since the disease is recessive, she will not be affected by the disease, since she has one healthy X chromosome and one disease-carrying one. 

If the child is a girl, there is a 0% chance that she will have the disease (although she will be a carrier). 

If the child is a boy, there is a 100% chance that he will inherit the disease. 

The answer is D)

Dna strands are split apart to allow an opening for replication. the opening has two replication forks so synthesis goes toward them in 5' to 3' direction.