Question

In a sample of organisms consisting of 10AA, 15Aa and 4aa individuals, what are the allele frequencies in this sample?

• A. A = 0.6; a = 0.40
• B. A = 0.4; a = 0.60
• C. A = 0.6; a = 0.6
• D. A = 0.4; a = 0.4

Answer 1

The correct option is A A = 0.6; a = 0.40

According to the hardy Weinberg principle,
$p^2+2pq+q^2=1$
From the question, we can calculate the total number of organisms in a sample = 10+15+4 = 29 organisms of which 10 individuals have the genotype AA (represented as $p^2$ in the above equation), 15 have Aa (represented by 2pq), and 4 have aa (represented as $q^2$. The value to be calculated is that of p and q which represents the frequency allele A and a. From the above data,
$p^2$ = 10/ 29 = 0.34
therefore p= square root of 0.34 = 0.58 = 0.6
thus the allele frequency of allele A in the population is 0.6
$q^2$ = 4/29 = 0.13
therefore q = square root of 0.13 = 0.36 = 0.4
thus the allele frequency of allele a in the population is 0.4