The gene frequency for a dominant allele is 0.68 and the recessive allele is 0.39. What percent of the population has a homozygous recessive genotype?

15.21 %

Explanation:

If we recall the basic formula of Hardy-Weinberg's equilibrium; we have the following below:

p + q = 1

p² + 2pq + q² = 1

where;

p = frequency of the dominant allele in the population

q = frequency of the recessive allele in the population

p² = percentage of homozygous dominant individuals

q² = percentage of homozygous recessive individuals

2pq = percentage of heterozygous individuals

Given that p = 0.68 and q = 0.39

the percentage of the homozygous recessive genotype (q²) will be

(0.39) ² = 0.1521

= 0.1521 * 100

= 15.21 %

∴ the percentage of the population that has a homozygous recessive genotype = 15.21 %