# The gene pool of a large population of fruit flies contains only two eye-colour alleles: the dominant red?

allele, W & the recessive white allele, w. Only 1% of the population has white eyes. Determine the allele & genotype frequencies of this population??

### 1 Answer

- LarkinLv 51 decade agoFavorite Answer
Use the Hardy-Weinberg equation:

p^2 + 2pq + q^2 = 1

p^2 is the frequency of the WW genotype.

q^2 is the frequency of the ww genotype.

2pq is the frequency of the Ww genotype.

To have white eyes the flies must have the genotype ww.

The question tells you that 1% of the population has white eyes, so the frequency of the ww genotype = 0.01 = q^2.

From this you can work out q.

q=0.1. This is the frequency of the w allele.

Now you can work out p, by using the equation p + q = 1.

So p = 0.9, which is the frequency of the W allele.

Therefore the frequency of the WW genotype = p^2 = 0.9^2 = 0.81.

The Ww genotype has the frequency 2pq = 2 x 0.9 x 0.1 = 0.18.

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