How to count gene frequency?


in population, there are a lot of gene forming the trait seen on people. some genes are dominantly appear, while some other are ressessive. in between these two, some genes are intermediately affecting the phenotype of a person.


so, how could we count the frequency of gene inside population?

here we use  Hardy Weinberg equation:

Gene Frequency:  [(2 x homo-zygote) + (hetero-zygote)] / 2 x population


let’s say there are two alleles in population, ‘p’ and ‘q’, means that there will be some type of genotype in population: ‘pp’, ‘pq’ dan ‘qq’

so in order to count the frequency of ‘p’ :

Gene Frequency:  [(2 x pp) + (pq)] / 2 x population

meanwhile to count the ‘q’ :

Gene Frequency:  [(2 x qq) + (pq)] / 2 x population

total frequency of p+q = 1

pp is the total genotype ‘pp’ in population

pq is the total genotype ‘pq’ in population

qq is the total genotype ‘qq’ in population