Which is the most common mechanism of genetic variation in the population of sexually reproducing organisms?

The correct option is A

Recombination

The correct option is option A.

Explanation of correct option:

1. Recombination is the process by which DNA stretches are recombined to form new allele combinations.
2. Two homologous chromosomes cross across and exchange genetic material during meiosis in sexual organisms.
3. New allele combinations are created by the breaking and recombining of DNA fragments.
4. The genetic variation that results from this recombination process at the gene level reflects variations in the DNA sequences of various species
5. It is the cause of genetic variation in different organisms of the same species.

Explanation of incorrect options:

Option B:

Chromosomal aberrations are the changes in the structure or number of chromosomes.

Option C:

A random sampling of organisms causes genetic drift, which is a shift in the number of existing genes in a population.

Option D:

It is the transfer of genetic material from one bacterium to another. Viral vector mediation is called transduction.

Final answer: Recombination is the most common mechanism of genetic variation in the population of sexually reproducing organisms.