In a population of Mendel's garden peas, the frequency of green-flowered plants (genotype aa) is 49%. The population is in Hardy-Weinberg equilibrium. What are the frequencies of the AA and Aa genotypes?
A)49% AA, 2% Aa
B)9% AA, 42% Aa
C)42% AA, 9% Aa
D)33% AA, 18% Aa
E)The frequencies cannot be determined from the information provided.

Question

Quizplus · Accepted Answer

Given that the frequency of aa is 49% (or 0.49), we can calculate the frequency of the a allele as the square root of 0.49, which is 0.7. Since the total frequency of all alleles must equal 1, the frequency of the A allele is 1 - 0.7 = 0.3. The frequency of AA is the square of the frequency of the A allele (0.3^2 = 0.09 or 9%), and the frequency of Aa is 2 * (frequency of A) * (frequency of a) = 2 * 0.3 * 0.7 = 0.42 or 42%.

In a Population of Mendel's Garden Peas, the Frequency of Green-Flowered