Hemophilia is an inherited bleeding disorder where the blood does not clot properly. This disorder is caused by a recessive allele on the X chromosome, a couple just learned that their daughter has hemophilia. They already have a son home does not have the disease. What are the genotypes of the couple and the two siblings? Explain you answer.

Since the gene that transmits hemophilia is linked to the X chromosome (), for a couple to have a hemophiliac daughter, the father must present the disease and the mother must be a carrier. Therefore, the parents' genotypes are and , while the daughter and son genotypes are and XY, respectively

Explanation:

An X-linked recessive gene -as in the case of hemophilia- will only be expressed in males with the affected X chromosome or in females who are homozygous for that gene.

The cross between the hemophilic father and the carrier mother can be seen in the following diagram:

Alleles                     Y

                  Y

X                X           XY

Where the possibility of having a healthy son and at least one daughter with hemophilia is evident.

Learn more:

Sex linked inheritance link

cuz he is really really short, assuming an unorthodox and inherently unlucky configuration of elevator buttons…

explanation: