In a large flock of 6520 sheep, 53 of them have yellow fat while the rest of the flock members have white fat. Yellow fat is inherited as a recessive trait. Assuming the population is in Hardy-Weinberg equilibrium, how many of the white fat sheep will have a homozygous dominant genotype?

number of sheep with homozygous dominant white fat genotype = 5399

Explanation:

If p = frequency of dominant allele and q = frequency of recessive allele

According to Hardy-Weinberg equilibrium:

p + q = 1 and p² + 2pq + q² = 1

where p² = frequency of homozygous dominant genotype

q² = frequency of homozygous recessive genotype

and 2pq = frequency of heterozygous genotype

Here,

q² = 53/6520 = 0.0081

q = √0.0081 = 0.09

p = 1-q = 1-0.09 = 0.91

So, p² = 0.91² = 0.8281

number of sheep with homozygous dominant white fat genotype = 0.8281*6520 = 5399