Question

A population consists of 300 individuals where 58 of them are homozygous for the red color allele (A) and 120 of them are homozygous for the blue color allele (a). What is the frequency of individuals with an Aa genotype in the population?

Answer 1

The answer is 0.41 or 41%.

According to the Hardy-Weinberg principle: p² + 2pq + q² = 1 

where:

p² - frequency of homozygous dominant individuals (AA)

q² - frequency of homozygous recessive individuals (aa)

2pq - frequency of heterozygous individuals (Aa)

So, if there are 300 individuals in a population, and 58 of them are homozygous dominant individuals (AA), then:

$p^{2} = \frac{58}{300}= 0.19$

Similarly, if there are 300 individuals in a population, and 120 of them are homozygous recessive individuals (aa), then:

$q^{2} = \frac{120}{300} =0.4$

Using the Hardy-Weinberg principle p² + 2pq + q² = 1, the frequency of heterozygous individuals (Aa) is 2pq = 1 - p² - q²:

2pq = 1 - 0.4 - 0.19

2pq = 0.41

Thus, the frequency of individuals with an Aa genotype in the population is 0.41 or 41%.