Question

A woman who is a carrier for hemophilia marries a man who does not have hemophilia. What are the chances of them having a son or daughter with hemophilia? Show your work.

Answer 1

The chances are 50/50.

They can have 1 son with it, or they can 1 son without it. They can also have 1 daughter with it, or they have 1 daughter without it.

Hope this helps!! (:

Answer 2

If a woman has hemophilia and marries a man who does not have hemophilia, she will have a 25% chance of having a son with hemophilia, a 25% chance of having a daughter with hemophilia, a 25% chance of having a son without hemophilia and a 25% chance of having a daughter without hemophilia.

This is due to hemophilia being conditioned by the recessive gene "h", carriers of the "H" gene do not have the disease. Thus, a woman with the disease would have the
`X^(H) X^(h)` genes, while a man without the disease would have the
`X^(H) Y^(H)` genes. The cross between these two would be
`X^(H) X^(h)` x
`X^(H) Y^(H)` =
`X^(H) X^(H)`(daughter without hemophilia),
`X^(H) X^(h)` (daughter with hemophilia),
`X^(H) Y^(H)` (son without hemophilia),
`X^(h) Y^(H)` (son with hemophilia).