Question

f there are 100 individuals in a population and 20 are homozygous for B, 60 are heterozygous, and 20 are homozygous for b, what is the allele frequency of B? 80 percent

Answer 1

The Hardy-Weinberg equilibrium is a principle stating that the genetic variation in a population will remain constant from one generation to the next in the absence of disturbing factors. When mating is random in a large population with no disruptive circumstances, the law predicts that both genotype and allele frequencies will remain constant because they are in equilibrium.

   The Hardy-Weinberg model consists of two equations: one that calculates allele frequencies

                                 p + q = 1

When we calculate the frequency of B alleles
We add the B alleles of 20 from BB individuals and 30 from Bb individuals
B=20+30=50
The value 50 is divided by all the values of BB,Bb and bb which is (20,60 and 20) which will be 100
=50/100
=0.5
When the value 0.5 is multiply with the 100 we get the frequency as below for the allele B
=0.5 x 100
= 50%

Whereas the frequency of b value will also be 0.5 when both the values of B and b it makes the value to 1

                           =p+q=1

                          = 0.5+0.5=1