Question

Problem:

In a given population, only the "A" and "B" alleles are present in the ABO system; there are no individuals with type "O" blood or with O alleles in this particular population.

• If 200 people have type A blood, 75 have type AB blood, and 25 have type B blood, what are the alleleic frequencies of this population (what are p and q)?

Please answer, Hardy-Weinberg Problem

Answer 1

Let p and q be allelic frequencies for alleles A and B respectively.

Total population = 200+75+25 = 300

Individuals with type A blood are homozygous AA,

individuals with type AB blood are heterozygous AB, and

individuals with type B blood are homozygous BB.

The frequency of A (p) = [2 x (number of AA) + (number of AB)] /[2 x (total number of individuals)].

p = [2 x (200) + (75)] / [2 x (300)].

or p = 475/600 = 0.792

Since q = 1 - p (Hardy-Weinberg equilibrium),

then q = 1 - 0.792 = 0.208.

Hence, p = 0.792, q = 0.208