Question

The sum total of all the allelic frequencies of a gene in a Hardy - Weinberg population is

• A. >=1
• B. Always 1
• C. <≠0
• D. >1

Answer 1

The correct option is B Always 1

According to the Hardy - Weinberg principle, allele frequencies in a population are stable and constant from generation to generation if the population is not undergoing evolution. The equation to represent this equilibrium is: p + q = 1, where p and q are frequencies of dominant and recessive alleles in the population, whose binomial expansion is expressed in the form of $p^2+2\mathrm{pq}+q^2=1$,
where $p^2$ is the genotypic frequency of homozygous dominant 2pq is the frequency of heterozygous, and $q^2$ is the frequency of homozygous recessive in a population.
So either allele frequencies or genotype frequencies, the sum total of all remains equal to one in the population, according to Hardy - Weinberg equilibrium.