Bio Destroyer #92(2011) Genetics

[KyoPhan]

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92) A colorblind man marries a normal woman. If they have children, what is the probability that their son will be colorblind.

How do we know that the normal woman isn't a carrier? The answer says that the woman is XX and the man is X+Y, thus answer they came up with is 0%.

Colorblindness is a sex-linked gene. I did the punnet square for both.

They both gave different answers.

 

[herkulease]

I believe he has another question like this but clearly states the father of the mother is color blind telling you she is a carrier.

should get a question like this on the test they'll clearly tell you the case.

 

[toothhornet88]

92) A colorblind man marries a normal woman. If they have children, what is the probability that their son will be colorblind.

How do we know that the normal woman isn't a carrier? The answer says that the woman is XX and the man is X+Y, thus answer they came up with is 0%.

Colorblindness is a sex-linked gene. I did the punnet square for both.

They both gave different answers.

yeah their question is very unfair: because you can have either 50% or 0% chance depending if she is a carrier or not. The question is not a good one. It should have had some type of information on the parents of the woman.

I guess when they mean normal you just have to assume they mean a non-carrier, even though it's not the best assumption in general

 

[KyoPhan]

Alright, thx guys. Just wanted to make sure I was thinking correctly.

 

[jorourk1]

Alright, thx guys. Just wanted to make sure I was thinking correctly.

you have awesome handwriting haha

 

[FROGGBUSTER]

I took a genetics course last semester. Whenever they refer to a normal woman in problems dealing with sex-linked traits, you assume she is homozygous recessive. The reason is just because most of these sex-linked diseases are very rare. Also, a woman would presumably know if her family has a history of the disease, in which case she would either be a carrier or homozygous recessive.

 

[KyoPhan]

you have awesome handwriting haha

Haha, that's the first time I've been complimented for my handwriting.

I took a genetics course last semester. Whenever they refer to a normal woman in problems dealing with sex-linked traits, you assume she is homozygous recessive. The reason is just because most of these sex-linked diseases are very rare. Also, a woman would presumably know if her family has a history of the disease, in which case she would either be a carrier or homozygous recessive.

Interesting, I will keep that in mind. Also do you mean homozygous recessive or dominant? I was under the impression that most disorders are from homozygous recessive.

 

[FROGGBUSTER]

Haha, that's the first time I've been complimented for my handwriting.



Interesting, I will keep that in mind. Also do you mean homozygous recessive or dominant? I was under the impression that most disorders are from homozygous recessive.

Yeah my bad, homo dominant.

 

[toothhornet88]

you have awesome handwriting haha

well doctor/dentist are known for the "best" handwriting lol

 

[KyoPhan]

Destroyer later goes on to a similar prob in #148(2011).

This time they say the normal woman had a colorblind mother.

Another bad wording on question for colorblindness for #170(2011).

 

[wizi]

Destroyer later goes on to a similar prob in #148(2011).

This time they say the normal woman had a colorblind mother.

Another bad wording on question for colorblindness for #170(2011).

Read froggbuster post above and you will understand why he did not point out whether the mother is a carrier or not.