Question

In the Hardy-Weinberg equation, the frequency of heterozygous individuals is represented by:
(a) ${ q }^{ 2 }$
(b) ${ p }^{ 2 }$
(c) 2pq
(d) pq

Answer 1

Hint: The Hardy- Weinberg principle states that the frequency of occurrence of alleles of a gene for a given population will remain constant from generation to generation. This means that the gene pool which is the sum of the total genes and their alleles in a population remains constant.

Complete Step by Step Answer:
The Hardy-Weinberg principle is represented by an algebraic equation in which p denotes the frequency of allele ‘A’ and q denotes the frequency of allele ‘a’.
Thus, the equation is denoted as ${ p }^{ 2 }$ + 2pq + ${ q }^{ 2 }$ = 1
Here ${ p }^{ 2 }$ denotes the frequency of ‘A’ allele appearing on both the chromosomes i.e. homozygous dominant.
Similarly, ${ q }^{ 2 }$ denotes the frequency of ‘a’ allele appearing on both the chromosome i.e. homozygous recessive.
So that means that 2pq represents the frequency of ‘A’ and ‘a’ appearing on each chromosome as in heterozygous condition.
So, the correct option is ‘(c) 2pq’.

Additional Information:
Any change in the measured frequency values would indicate the extent of evolutionary change that occurred in that population.
There are a total of 5 factors that affect the Hardy- Weinberg equilibrium. They are mentioned below as follows:
- Gene migration or gene flow
- Genetic drift
- Mutation
- Genetic recombination
- Natural selection

Note:
- The sum of all the allelic frequencies in a population will be 1.
- The founder effect is the phenomena in which the allelic frequency in the new population sample is so different from the original, that it becomes a new species.