Question

Genetic drift operates only in population which is
A) In island
B) Smaller
C) Larger
D) Mendelian

Answer 1

Hint:Evolution among species of any population is not just because of natural selection or adaptation; it also takes place due to migration of flow of gene from one population to another. It is a random process that helps in increasing genetic variation.

Complete answer:
We know that evolution is the changes that are adapted by a population to survive. In the same way gene flow that is also considered as migration is a part of evolution. It is the movement of an organism and its genetic materials from one population to another. Gene flow includes many different events like pollen being blown to new people to new places. So, gene flow takes place between the two populations of the same organisms with the help of migration and maintained by vertical transfer of gene and reproduction to the offspring from the parents. It is an important mechanism of transferring the diversity in the gene within the population. It changes the genetic diversity distribution among the population by allele frequency modification. The main effect of gene flow is it increases the genetic variation of the population, however, the genetic difference among the population decreases when the gene flows between genetically distant populations.

Now, genetic drift is the change in the allele frequency of a population from one generation to another that takes place due to change in events. The genetic drift is the change that occurs due to sampling error during the allele’s selection from the next generation from the gene pool. The allele frequency of a population is the fraction of the copies of one gene that share a specific form. The genetic drift sometimes causes gene variants to disappear completely and thus reduces the genetic variation. It initially causes rare alleles to become more frequent and even fixed. The genetic drift takes place in populations of all sizes but the effect tends to be stronger in small populations.

Thus, the correct option is ‘D’. Smaller.

Note:The gene flow and genetic drift change the frequency of allele of a population. In genetic drift the gene is passed down and the allele frequency changes in the population. The gene flow is random but can be controlled by genetic drift and natural selection.