Question

In a certain population, the frequency of three genotypes is as follows:

Genotypes: BB Bb bb

Frequency: $22\%$ $62\%$ $16\%$

What is the likely frequency of B and b alleles?

Answer 1

Introduction:

The dominant or recessive allele is present in the homozygous condition as well as heterozygous.

Therefore the total frequency of an allele in the given genotypes will the summation of the frequency of the allele in the homozygous condition and half the frequency in the heterozygous condition (considering a heterozygous condition will have half the number of dominant and half the number of recessive alleles)

Formula:

Frequency of allele B= frequency of BB + $\frac{1}{2}$ of Bb

Frequency of allele b= frequency of bb + $\frac{1}{2}$ of Bb

Given data:

Frequency of BB= 22

Frequency of Bb= 62

Frequency of bb= 16

Substitution and calculation:

Frequency of allele $B=22+\left(\frac{1}{2}\right)\times 62=53\%$

Frequency of allele $b=16+\left(\frac{1}{2}\right)\times 62=47\%$

Final answer:

Frequency of allele $B=53\%$

Frequency of allele $b=47\%$