You sample a population of butterflies and find that 56% are heterozygous at a particular locus. What should be the frequency of the recessive allele in this population?

A. 0.07

B. 0.08

C. 0.09

D. 0.70

The correct answer is Not Available

Explanation:

From the Hardy Weinberg Law of Population and Genetics,

We have

x²+2xy+y²=1 and

x+y=1

where

x = frequency of the dominant allele in the population

y = frequency of the recessive allele in the population

x2 = percentage of homozygous dominant individuals

y2 = percentage of homozygous recessive individuals

2xy = percentage of heterozygous individuals

Given 2xy = 0.56

from here, y=0.28/x, (the frequency of the recessive allele) can be obtained

we need to find 'x'

recall, x+y=1, x=1-y

substituting this gives us

y=0.28 / (1-y), which becomes,

y (1-y) = 0.28

y2-y+0.28 (quadratic equation)

Solving this to find 'y' gives two imaginary values of y

There is no imaginary solution among the options and hence No answer.