TBR Genetic Info Passage 5

[ModernAlchemist]

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I was confused about a few passages in this section, but..

Most of all, Passage V:

The information in the passage provides percentages for frequency of the color-blindness (x-linked recessive) trait in the population with regards to males. It talks about 2 different loci that contribute to this and then goes on to ask about females with regards to expression of this trait. The explanation indicates that you can just take the frequency of the trait in males as the allelic frequency, q, for all the entire population and then females would just be q^2, assuming only one genetic loci were involved. Then you can do the same thing for the frequency from different color-blindness loci (red vs green). Now, maybe I'm missing something, but I'm not understanding how you can just use that as the allelic frequency to for calculations with the female population. Can anyone explain this?


This section seemed a little intense, passage-wise. Did anyone who took the actual MCAT think the genetics on it was this difficult?

 

[ModernAlchemist]

For anyone who was interested, I found the explanation to this on the Khan Academy video (skip to 11:00 minutes):

http://www.khanacademy.org/video/sex-linked-traits?playlist=Biology


I hate it when threads don't have resolutions and I need an answer so there you go.