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

Frequency of dominant allele
`= 0.55`

Frequency of recessive allele
`= 0.45`

Step-by-step 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`
`= (20)/(100)`

`q = √(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`