(a) How is Hardy-Weinberg's expression “(p2 + 2pq+q 2) = 1”derived?
(b) List any two factors that can disturb the genetic equilibrium.
- Sum Total of All the Allele Frequencies is 1: Let there be two alleles A and a in a population. The frequencies of alleles A and a are ‘p’ and ‘q’ respectively. The frequency of AA individuals in a population is p 2 and it can be explained that the probability that an allele A with a frequency of p would appear on both the chromosomes of a diploid individual is simply the product of the probabilities, i.e., p 2 . Similarly, the frequency of aa is q 2 and that of Aa is 2pq.p 2 + 2pq+q 2 ) = 1,where p 2 represents the frequency of homozygous dominant genotype, 2pq represents the frequency of the heterozygous genotype and q 2 represents the frequency of the homozygous recessive.
- Factors that affect Hardy–Weinberg equilibrium:
- Gene migration or gene flow
- Genetic drift
- Genetic recombination
- Natural Selection