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