Question

1.)A couple has just learned that their daughter has hemophilia. They already have a son who does not have the disease. What are the genotypes of the couple? Explain your reasoning.
ANWSER:They are both likely carriers of the disease, therefore they'd have the recessive gene somewhere but not on both chromosomes of the homologous pair.
Am im correct?!

Answer 1

Not my thing, sorry but based on what little I remember that sounds correct.

Answer 2

Not correct. the keyword here is Daughter. Hemphilla both types, A and B, are carried on the X genes. So if it had been a son who had the disease, you would be correct.

However, daughters carry two X chromosomes, one from Mom, and one from Dad. We have bad news for Mom, if daughter has type A or B hemophilia, Mom has the defective gene on her one X, and it is likely she will get hemphilia.

But if Mom has no symptoms, then it well may be Type C hemophilia, which is non sex linked. The first question to be asked are mom and dad ews of Ashkenazi (east European) descent. If so, then your original answer is probably correct.

Life is not always simple. Females have XX gentoype, and males have XY. Sons get one x from mom, and the Y from dad. Daughters get an X from both parents.

Daughters getting hemophilia is so rare, if I were the physician, I think I would order a genetic test of daughter and parents to verify that in fact the couple is the genetic parents. If sex linked, Mom has to have a defective gene...

Answer 3

Thanks