Question

In humans, the condition for normal blood clotting (H) dominates the condition for non clotting (hemophilia) (h). Both alleles are linked to the X chromosome. A male hemophiliac marries a woman who is a carrier for this condition. (In this respect, a carrier is a woman who has an allele for normal blood clotting and an allele for hemophilia.) If they have a son, what are the chances he will be normal for blood clotting

Answer 1

Answer:

The correct answer would be - 50%.

Explanation:

Hemophilia is a sex-linked recessive disorder that takes place in males more than in females as females have two X chromosomes so if one is affected other still able to make clotting factors but in males, there are only one x chromosome.

If a hemophilic man XhY marries with a carrier women XHXh then the chances of their son for normal blooding would be :

Gametes:

Male: Xh and Y

Female: XH and Xh

Then cross:

             Xh                          Y

XH      XHXh                     XHY

    (carrier daughter)      (normal son)

Xh        XhXh                    XhY

 (hemophilic daughter)  (hemophilic son)

Thus, the chances of normal son is 50% among sons