Which of the following factors cause a disturbance in Hardy-Weinberg equilibrium?
(A) Gene migration or gene flow
(B) Genetic stability
(C) Natural selection
(D) Genetic drift
Choose the correct answer from the options given below:
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → (A), (C) and (D) only
The Hardy-Weinberg principle says that allele frequencies in a population stay constant from generation to generation. Five factors disturb this equilibrium: gene migration or gene flow, genetic drift, mutation, genetic recombination and natural selection. When the frequencies change, evolution has taken place.
(A) Gene migration or gene flow — Included. Alleles enter or leave the population when individuals move, so the frequencies change.
(B) Genetic stability — Not included. Stable allele frequencies are the Hardy-Weinberg equilibrium itself. They are not a factor that disturbs it.
(C) Natural selection — Included. Individuals with favourable alleles leave more offspring, so these alleles become more common.
(D) Genetic drift — Included. Allele frequencies change by chance, and the effect is strongest in small populations.
Note: A similar question was also asked in CUET (UG) 2025 on 22-05-2025 (Slot 2).
NCERT Extract:
Hardy-Weinberg Principle – …
