Question

A population of aphids living on a bush suffer different levels of predation based on a color associated with a single dominant gene that has two alleles. The dominant color is green (GG or Gg) and the recessive color is olive (gg). In a population of 100 individuals there are 80 green aphids and 20 olive aphids. You find that there are 50 heterozygotes. What are the allele frequencies of G and g, respectively

Answer 1

Answer:

Frequency of dominant allele $= 0.55$

Frequency of recessive allele $= 0.45$

Explanation:

It is given that  olive color is a recessive trait.

As per Hardy Weinberg's equation-

p signifies the frequency of dominant allele in a given population and q signifies the frequency of recessive allele in a given population.

Also as per the first law of Hardy Weinberg's equilibrium , sum of allele frequencies is equal to one for a given population.

Thus

$p+q = 1$

Frequency of recessive individuals is represented by $q^2$

Here, $q^2$ $= \frac{20}{100}$

$q = \sqrt{0.2} \\q = 0.45$

Thus, frequency of dominant allele i.e G is equal to

$1-0.45\\= 0.55$

Frequency of dominant allele $= 0.55$

Frequency of recessive allele $= 0.45$