A man and woman marry. They have five children, 2 girls and 3 boys. The mother is a carrier of
hemophilia, an X-linked disorder. She passes the gene on to two of the boys who died in childhood
and one of the daughters is also a carrier. Both daughters marry men without hemophilia and have 3
children (2 boys and a girl). The carrier daughter has one son with hemophilia. One of the non-carrier
daughter’s sons marries a woman who is a carrier and they have twin daughters. What is the percent
chance that each daughter will also be a carrier?

Question

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Respuesta :

Oseni Oseni · Answer 1 · 2020-01-23T13:21:49+01:00

Answer:

50%

Explanation:

Since the disease is X-linked, males can either be affected or not while females can be affected, unaffected or a carrier for the disease.

Let the allele for hemophilia be h, the alternate will be H

Non-carrier mother's son is a not affected for the disease = [tex]X^H Y[/tex]

A woman who is a carrier = [tex]X^H X^h[/tex]

If the two mate: [tex]X^H Y[/tex] x [tex]X^H X^h[/tex]

Progeny: [tex]X^HX^H, X^HX^h, X^HY and X^hY[/tex]

Out of the two daughters, one is a carrier and the other is unaffected at all.

Hence, the chance of each daughter being a carrier is 50% or 1/2.