In a certain population, the frequency of allele A is 0.3 and the frequency of allele a is 0.7. The population inbreeds such that f = 0.1. What is the frequency of each genotype in the population?
A) AA: 0.09, Aa: 0.42, aa: 0.49
B) AA: 0.49, Aa: 0.42, aa: 0.09
C) AA: 0.01, Aa: 0.90, aa: 0.09
D) AA: 0.111, Aa: 0.378, aa: 0.511
E) AA: 0.21, Aa: 0.42, aa: 0.37

Question

Quizplus · Accepted Answer

First, we can calculate the expected genotype frequencies under Hardy-Weinberg equilibrium:

AA = p^2 = 0.3^2 = 0.09 
Aa = 2pq = 2(0.3)(0.7) = 0.42 
aa = q^2 = 0.7^2 = 0.49

Next, we can use the inbreeding coefficient (f) to adjust the genotype frequencies:

f = (observed heterozygosity - expected heterozygosity) / expected heterozygosity 
0.1 = (Aa - 2pq) / 2pq 
0.1 = (Aa - 0.42) / 0.84 
Aa = 0.42 + 0.1(0.84) = 0.498

Now we can calculate the other genotype frequencies:

AA = p^2 = 0.3^2 = 0.09 
Aa = 0.498 
aa = q^2 = 0.7^2 = 0.49

So the answer is D, with AA: 0.111, Aa: 0.378, aa: 0.511.

In a Certain Population, the Frequency of Allele a Is