Hemophilia Is Caused by an X-Linked Recessive Mutation in Humans

question 49

Multiple Choice

Hemophilia is caused by an X-linked recessive mutation in humans.If a woman whose paternal uncle (father's brother) was a hemophiliac marries a man whose brother is also a hemophiliac, what is the probability of their first child having hemophilia (Note: assume that there are no other cases of hemophilia in the pedigree and no hidden carriers) ?

• A)0
• B)1/4
• C)1/2
• D)1/8
• E)1

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Definitions:

-emesis

A suffix in medical terminology indicating vomiting.

-ectasis

A suffix used in medical terms to denote an expansion, dilation, or stretching of a structure or organ.

-staxis

A suffix used in medical terminology to denote bleeding or a hemorrhage, as in epistaxis (nosebleed).

-ptosis

A suffix indicating the prolapse, falling, or downward displacement of a body part.