Choose the correct statements about the factors affecting Hardy-Weinberg equilibrium from the following:
A. When a section of a population migrates to another place and population, gene frequencies change in the original as well as in the new population.
B. There would be a genetic drift if gene migration happens multiple times.
C. When the change in allele frequency in the new sample of population is so different that they become a different species, the effect is called founder effect.
D. Genetic recombination is one of the factors known to affect Hardy-Weinberg equilibrium.
Choose the correct answer from the options given below:
Answer & explanation
Correct answer: option 1
The correct answer is Option (1) → A, C and D only
NCERT names five factors that disturb Hardy-Weinberg equilibrium: gene migration or gene flow, genetic drift, mutation, genetic recombination and natural selection. Gene flow and genetic drift are close cousins, and the difference between them is the point of this question. Gene flow comes from repeated migration; genetic drift is a change in allele frequency that happens by chance.
A. When a section of a population migrates to another place and population, gene frequencies change in the original as well as in the new population. — True. New genes or alleles are added to the new population and the same are lost from the old one, so both populations change.
B. There would be a genetic drift if gene migration happens multiple times. — False. Gene migration happening multiple times gives gene flow. Genetic drift is the name for the same kind of change when it occurs by chance.
C. When the change in allele frequency in the new sample of population is so different that they become a different species, the effect is called founder effect. — True. The original drifted population becomes the founders of the new species, hence the name founder effect.
D. Genetic recombination is one of the factors known to affect Hardy-Weinberg equilibrium. — True. Genetic recombination is one of the five factors in the NCERT list.
NCERT Extract:
Hardy-Weinberg Principle – “… 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. New genes/alleles are added to the new population and these are lost from the old population. There would be a gene flow if this gene migration, happens multiple times. If the same change occurs by chance, it is called genetic drift. Sometimes the change in allele frequency is so different in the new sample of population that they become a different species. The original drifted population becomes founders and the effect is called founder effect.”