Genetic Probability (Binomial Expansion)

[fanofdean]

Homework Statement

I'm stuck on a problem with two variables in it. The question wants to know what's the probability of getting 2 boys and 2 girls, with one of the boys being albino. They say one parent is albino and the other is a heterozygous carrier, so the change of getting it is 50% in the children.
So by binomial expansion, it's 1 4 6 4 1. I know the two girls and two boys is the middle term with 6(p^2)(q^2) but with q and p being getting a boy or girl at .50 each. But how do I encompass the albino probability in this? Multiply each child by .50?

Homework Equations

(p^4)+4(p^3)(q)+6(p^2)(q^2)+4(q)(p^3)+(q^4)

The Attempt at a Solution

I can easily find the probability of getting two girls and two boys, I would simply use the 6(p^2)(q^2) with p and q being .50 respectively. I just don't know how to factor in the albino part.

 

[AGNuke]

Something like that. You should multiply with another binomial probability regarding the 4 children with "albino chromosome".

 

[Ygggdrasil]

Something like that. You should multiply with another binomial probability regarding the 4 children with "albino chromosome".

It might be easier to calculate the probability that the two girls lack albinism and the probability that one of the boys has albinism.