A population has two alleles for a particular gene A and a a

A population has two alleles for a particular gene, A and a, and is in Hardy-Weinberg equilibrium. The frequency of allele a is 0.2. What is the frequency of individuals with AA genotype?

0.2

0.4

0.64

0.04

0.8

Solution

C). 0.64

Hardy and Weinberg mathematically proved that in a population, all dominant and recessive alleles comprise all alleles for that gene.

This was mathematically represented as p+ q = 1.0

Where,

p = frequency of dominant alleles

q = frequency of recessive alleles.

Given that, the frequency of a = 0.2

As the population is in H-W equilibrium, the frequency of A = 1-0.2 = 0.8

The frequency of AA genotype = 0.8*0.8 = 0.64