Question

A population will not exist in Hardy-Weinberg equilibrium if
A. There is no migration
B. The population is larger
C. Individuals mate selectively – Correct
D. There are no mutations

Answer 1

Hint:Hardy-Weinberg equilibrium is affected by fire factors. These factors are gene migration or gene flow, genetic drift, mutation, genetic recombination and natural solution.

Complete answer
A. There is no migration: When migration of a population takes place from one place to another place, gene frequencies change in the original as well as in the new population. New genes/alleles are added to the new population. Gene flow will continue only if migration happens otherwise no gene flow takes place.
B. The population is large: If the population is large enough and changes in allele frequencies due to chance or accident are insignificant.
C. Individuals mate selectively: Hardy Weinberg principle states the population well has the given genotypic frequencies (i.e. called Hardy Weinberg equilibrium) after a single generation of random mating within the population. When random mating assumptions are violated the population will not have Hardy Weinberg proportion.
Hence population will not exist in Hardy Weinberg equilibrium if individuals mate selectively.
D. There are no mutations: Gene mutation is a random change in the base sequence of a gene. The mutated gene may give rise to a new protein or may fail to produce any. This may Change the phenotype (trait). Gene variation results in change in gene frequency.

The correct option is C, Individual mate selectively.

Note: Hardy-Weinberg principle states that allele frequencies in a population are stable and are constant from generation to generation. The gene pool and their alleles in a population remains constant. This is called Hardy-Weinberg’s equilibrium. Sum total of the allelic frequencies is 1. Gene frequency of total population is represented by: ${p^2} + 2pq + {q^2} = 1.$ Hence gene frequency will remain static only in the absence of evolutionary forces like mutations, selection, genetic drift and migration.