TBR Bio Q

[RiPSTONE]

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Hemophilia A results from a deficiency of factor VIII while hemophilia B results from a deficiency of factor IX. Genes coding for both hemophilias reside on the X chromosome and are genetically transmitted as a sex-linked recessive trait. What is the probability that a woman whose father has hemophilia, and who marries a normal man, will have an affected son?

A. 1.00
B. 0.75
C. 0.50
D. 0.25

I understand the explanation to the question as to why the answer is C, but they just assumed that that the mother of the woman whose father has hemophilia was normal. Is it safe to assume this on the MCAT?

 

[Czarcasm]

Hemophilia A results from a deficiency of factor VIII while hemophilia B results from a deficiency of factor IX. Genes coding for both hemophilias reside on the X chromosome and are genetically transmitted as a sex-linked recessive trait. What is the probability that a woman whose father has hemophilia, and who marries a normal man, will have an affected son?

A. 1.00
B. 0.75
C. 0.50
D. 0.25

I understand the explanation to the question as to why the answer is C, but they just assumed that that the mother of the woman whose father has hemophilia was normal. Is it safe to assume this on the MCAT?

Yeah, seems strange they wouldn't include the mothers genotype, but I suppose it's a reasonable assumption given how the question is asked. I've seen a fair share of unusual questions in previous examinations, but I think they atleast try to make questions as clear as possible.