Hemophiliacs have blood that does not coagulate well, and they often die at a young age. The disease allele is recessive and X-linked. Which genetic possibilities can be predicted for the offspring of a hemophiliac male and a nonhemophiliac female who is a carrier for the disease?
A) All children would be hemophiliac.
B) All females would be hemophiliac.
C) All males would be hemophiliac.
D) Some males and females could be hemophiliac.

Question

Quizplus · Accepted Answer

Since the male is hemophiliac, he only has one X chromosome, which means that all of his daughters will inherit the hemophilia allele and be carriers, but not express the disease. For his sons, they will inherit the Y chromosome from their father and the X chromosome from their mother. If the mother is a carrier, there is a 50% chance that her X chromosome will have the hemophilia allele, making the son hemophiliac. Therefore, some males and females could be hemophiliac.

Hemophiliacs Have Blood That Does Not Coagulate Well, and They