Genetics question

[tRNA]

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Hi All, here's a genetics quest. for you from kaplan white book

If a male hemophiliac (X^h Y) is crossed with a female carrier of both color-bllindness and hemophilia (X^c X^h), what is the probability that a female child will be phenotipically normal?

A) 0%
B) 50%

I thought the answer should be A, but the correct answer is B....I see where they got the 50% from...bec. the female progeny will be:
(X^c X^h)(X^h X^h) so I guess they are referring to this progeney: (X^c X^h) as phenotipically "normal" but the last time I checked color blindness is also a recessive sex-linked disease in humans just as hemophilia is so why wouldn't the answer be 0%, since both progeny will be affected with either disease and hence neither is Phenotipically "normal".....the question didn't indicate that they want the answer with respect to hemophilia alone so how can in the world am I supposed to figure out that they want the answer with respect to hemophilia only, its not stated clearly in the question!!
I guess I am having trouble interpreting the question
pleeeeez help thanks

 

[chordata]

If you look at the cross like this X^Ch Y and X^cH X^Ch, the combinations for females are:
X^Ch X^cH and X^Ch X^Ch

since hemophilia and colorblind traits are recessive only the second combo will show the hemophilia phenotype. The other will be heterzygous.

C=dominant (color)
c=recessive (colorblind)
H=dominant (normal)
h=recessive (hemophilia)

 

[heshyn2000]

Hi All, here's a genetics quest. for you from kaplan white book

If a male hemophiliac (X^h Y) is crossed with a female carrier of both color-bllindness and hemophilia (X^c X^h), what is the probability that a female child will be phenotipically normal?

A) 0%
B) 50%

I thought the answer should be A, but the correct answer is B....I see where they got the 50% from...bec. the female progeny will be:
(X^c X^h)(X^h X^h) so I guess they are referring to this progeney: (X^c X^h) as phenotipically "normal" but the last time I checked color blindness is also a recessive sex-linked disease in humans just as hemophilia is so why wouldn't the answer be 0%, since both progeny will be affected with either disease and hence neither is Phenotipically "normal".....the question didn't indicate that they want the answer with respect to hemophilia alone so how can in the world am I supposed to figure out that they want the answer with respect to hemophilia only, its not stated clearly in the question!!
I guess I am having trouble interpreting the question
pleeeeez help thanks

Do you agree that the mother is phenotipically normal? since a female must have both X^c for her to be effected by a sex linked disease. well one girls genotype is just like her mother.