Question

Change in allele frequency by chance takes place due to genetic drift. The major effect of genetic drift takes place on

• A. A small, isolated population
• B. A large, isolated population
• C. Two widespread, interbreeding populations
• D. Two geographically isolated, large populations
• E. Two isolated, interbreeding populations

Answer 1

The correct option is A A small, isolated population

Genetic drift is the change in gene frequency in successive generation of a small population due to chance alone rather than natural selection or gene transfer. The effect of genetic drift on a small population is large as compared to that in the larger population which, owing to its large size and a large number of gametes produced, has the greater probability to accurately represent the allelic frequency of the parental population. Thus, a major effect of genetic drift is in small isolated populations.

Therefore, the correct answer is option A.