Question

Hemophilia is a hereditary disease that prevents a persons blood from clotting correct;y. The gene responsible for blood clotting is located on the X chromosome of the sex chromosome pair (X and Y. This is called x-linked inheritance. The dominant gene is H and the recessive causing hemophilia is h. Anyone with the dominant gene will not inherit hemophilia. Mother (X^h, X^H) and father (X^H and Y) have children X^H X^H, H^H X^h, X^H Y, and X^h Y. What are the chances of a child having hemophilia. WHy?

Answer 1

I looked at the diagram on wikipedia and it shows the exact same diagram that I have except the one on wikipedia is clearer. SO there would be a 75% chance that their children do not have hemophilia. Thank-you

Answer 2

• So the mother is normal XX The father is color blind XiY (the i indicates that the gene is affected) To be color blind and hemophiliac a woman needs to have XiXi and a man needs XiY This is both the same for color blindness and hemophilia. A woman can also be XiX. This would mean she is a carrier of the affected gene but not affected by the disease. Their daughters will all be carriers because only the X chromosome of the man is affected. This drawing explains it:
Fathermother
Theire daughter with genotype XXi marries a man with genotype XY (the daughter is carrier for both color blindness and hemophilia) If they get children they'll end up according to the next drawing:
femalemalemother father
So the chance that their son will have both the diseases is 50%
1 out of 4
50%