Question

Color in McIver beetles is determined by two alleles at one gene locus. McIver beetles must have a heterzygous genotype (genotype A1A2) in order to have a brown color phenotype. Calculate the frequency of the brown beetles in the population if the frequency of the A1 allele is 0.8.

Answer 1

Answer: The frequency of brown beetles is 0.32.

Explanation: The frequency of A1 allele is 0.8. As p+q=1, or the sum of dominant and recessive frequencies equals 1 or 100%:

1 - 0.8 = 0.2

In Hardy-Weinberg principle,

$p^{2} + 2pq + q^{2} = 1$

2pq represents the frequency of heterozygote individuals, so:

genotype A1A2 = 2*0.8*0.2 = 0.32.

Thus, the frequency of brown beetles (A1A2) in the population is 0.32.