Question

A population is in Hardy-Weinberg Equilibrium with respect to a gene, "yellow," which has 2 alleles, y and Y. Y, the wild type allele, is completely dominant to y, and results in green pigment; yy results in yellow pigment. The frequency of the yy homozygote is 0.09. The frequency of the Y allele is ____; the frequency of the y allele is ____; the frequency of the YY homozygote is ___; the frequency of the Yy heterozygote is ___.

Answer 1

Answer:

The frequency of the Y allele is 0.7

The frequency of the y allele is 0.3

The frequency of the YY homozygote is 0.49

The frequency of the Yy heterozygote is 0.42

Explanation:

According to Hardy-Weinberg Equilibrium,

p + q = 1

p² + 2pq + q² = 1

where,

p = frequency of dominant allele

q = frequency of recessive allele

p² = frequency of dominant homozygous genotype

2pq = frequency of heterozygous genotype

q² = frequency of  recessive homozygous genotype

Here,

yy = q² = 0.09

frequency of y allele = q = √0.09 = 0.3

frequency of Y allele = p = 1-q = 1-0.3 = 0.7

p² = YY = (0.7)² = 0.49

2pq = Yy = 2 * 0.7 * 0.3 = 0.42