Tim and Stephanie are devastated when they find out their newborn son has hemophilia - an x- linked recessive disease. Tim is shocked because neither he nor his wife have hemophilia. He
figured if his son has the disease, he must have gotten it from him. Is Tim correct in his
thinking? Explain. Also explain what genotypes Tim and his wife must have for neither of them
to have the disease, but to have a son who has it.

First of all, hemophilia is an x-linked recessive and recessive disease. So it's a genetic disease.

Therefore, there is no possibility of snatching it from his son. It can come from mom or dad. If the mother and father do not have this disease, as in the question, the mother carries this disease recessively. If it was a girl, she would be less likely to get the disease, as she would have to inherit the genotype of this disease from both the mother and the father. however, since her children are boys, she received the disease gene from the mother's recessive gene region. Therefore, the boy has hemophilia in the XhY genotype.