Read the given passage and answer the questions that follow :-
In a given population one can find out the frequency of occurrence of alleles of a gene or a locus. This frequency is supposed to remain fixed and even remain the same through generations. Hardy-Weinberg principle stated it using algebraic equations. This principle says that allele frequencies in a population are stable and is constant from generation to generation. The gene pool remains a constant. This is called genetic equilibrium.
Which of the following factors affect Hardy-Weinberg equilibrium?
Answer & explanation
Correct answer: option 4
The correct answer is Option (4) → All of these
The Hardy-Weinberg equilibrium holds only as long as allele frequencies are not changed. NCERT lists five factors that affect it: gene migration or gene flow, genetic drift, mutation, genetic recombination and natural selection. All three factors in the options are in this list.
Option (1) Mutation — Correct statement, but it is only one of the correct points, so on its own it is not the answer. Mutation adds new alleles to the population, so the allele frequencies change.
Option (2) Genetic drift — Correct statement, but it is only one of the correct points, so on its own it is not the answer. Genetic drift is a change in allele frequencies that occurs by chance.
Option (3) Gene flow — Correct statement, but it is only one of the correct points, so on its own it is not the answer. Gene flow takes place when gene migration happens multiple times, and it changes gene frequencies in both populations.
NCERT Extract:
Hardy-Weinberg Principle – “… Disturbance in genetic equilibrium, or Hardy- Weinberg equilibrium, i.e., change of frequency of alleles in a population would then be interpreted as resulting in evolution. Five factors are known to affect Hardy-Weinberg equilibrium. These are gene migration or gene flow, genetic drift, mutation, genetic recombination and natural selection. When migration of a section of population to another place and population occurs, gene frequencies change in the original as well as in the new population.”