It is to be noted that:
1) The brown allele frequency is 60% and
The Black Allele frequency is 40%.
2) The allele frequency that is higher is that of the Allele for brown fur
3) The genotype for a homozygous brown mouse is bb
4) In a population of 200 mice, the number of homozygous black would be 32.
1) To derive the brown allele frequency, we say
= (number of Allele for brown fur/total Alleles) x 100%
= (12/20) x 100%
= 60%
Allele frequency for Black Allele =
100% - brown allele frequency
= 100% - 60%
= 40%
2) comparing the two allele frequencies it is clear that 60% is higher than 40%, thus, the allele frequency that is higher is that of the Allele for brown fur.
3) Recall that it is given that the allele for black fur is repreented as (B) while that of brown fur is (b).
If we have a homozygous Brown, which is made up of two allels, then the genotype will be bb.
4) From the pie chart, we can se that the homozygous black is 16%.
Thus, if in a population of 200 mice, 16% are homozygous, the actual number is:
16% x 200
= 32
Thus, in a population of 200 mice, the number of homozygous black would be 32.