Disturbance in the value of allele frequency in Hardy Weinberg equilibrium is directly proportional to the:
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → Extent of evolutionary change in a population
The Hardy-Weinberg principle says that allele frequencies in a population stay constant from generation to generation; this is genetic equilibrium. When the measured frequencies move away from the expected ones, the population is evolving, and the size of the change shows how much.
Option (1) Disturbance in gene flow — Incorrect. Gene flow is one of the causes that disturb the equilibrium, not what the disturbance measures.
Option (2) Extent of evolutionary change in a population — Correct. The difference from expected values indicates the extent of evolutionary change.
Option (3) Gene pool of a population — Incorrect. The gene pool is the total of genes and alleles in a population; it stays constant only while the equilibrium holds.
Option (4) Retention of original gene in new population — Incorrect. Keeping the original genes means no change, the opposite of a disturbance.
NCERT Extract:
Hardy-Weinberg Principle – “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 (total genes and their alleles in a population) remains a constant. This is called genetic equilibrium. Sum total of all the allelic frequencies is 1. Individual frequencies, for example, can be named p, q, etc. In a diploid, p and q represent the frequency of allele A and allele a . The frequency of AA individuals in a population is simply p2. This is simply stated in another ways, i.e., the probability that an allele A with a frequency of p appear on both the chromosomes of a diploid individual is simply the product of the probabilities, i.e., p2. Similarly of aa is q2, of Aa 2pq. Hence, p2+2pq+q2=1. This is a binomial expansion of (p+q)2. When frequency measured, differs from expected values, the difference (direction) indicates the extent of evolutionary change. 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.”