Explanation
The probability of a male child inheriting hemophilia from a mother who is a carrier and a father who has hemophilia is determined by the laws of genetics. Hemophilia is a sex-linked recessive disorder that is carried on the X chromosome.
A female carrier has two X chromosomes, one of which is affected by the hemophilia gene. When she has children, she has a 50% chance of passing on the affected X chromosome to each of her offspring. The other X chromosome that she passes on will be unaffected.
A male child inherits one X chromosome from his mother and one Y chromosome from his father. If the mother passes on the affected X chromosome, the male child will have hemophilia.
Therefore, the probability of a haemophilic son being born to a carrier mother and a haemophilic father is 50% or 1 in 2.
So the answer is C: 50%.
