Question

In a large herd of 5468 sheep, 76 animals have yellow fat, compared with the rest of the members of the herd, which have white fat. Yellow fat is inherited as a recessive trait. This herd is assumed to be in Hardy-Weinberg equilibrium. a. What are the frequencies of the white and yellow fat alleles in this population?

Answer 1

The Hardy-Weinberg equation is written as p²+q²+2pq = 1 and p + q =1

where,

p² is the frequency of homozygous dominant (BB)

q² is the frequency of homozygous recessive (bb)

2pq is the frequency of heterozygous (Bb)

p is the frequency of dominant allele (B)

q is the frequency of recessive allele (b)

As per given details, the number of homozygous recessive organisms in a population is 76.

Total population size is 5468

Thus, the frequency of homozygous recessive (q²) =
`(76)/(5468)`

⇒ q² = 0.014

⇒q =
`√(0.014)`

⇒q = 0.118

∴ p = 1 - 0.118

⇒p = 0.882

thus, the frequency of yellow fat allele is 0.118 and that of white fat allele is 0.882