Question

What is the most common mechanism of genetic variation in the population of a sexually reproducing organism?
A. Genetic drift
B. Recombination
C. Transduction
D. Chromosomal aberrations

Answer 1

Hint: Genetic variation is used to describe the variation in the DNA sequence in each genome. This variation makes it so unique whether in terms of hair colour, skin colour, etc.

Complete answer:Genes are the units of hereditary information, and they carry instructions for building proteins from the amino acids. Most organisms that reproduce sexually have two copies of each gene, because each parent cell or organism gives a single copy of its genes to its offspring. Morgan while experimented he found that when the two genes in a hybrid cross situated on the same chromosome, the proportion of parental gene combination were much higher than the non-parental type after this observation he coined the term recombination. Recombination is a significant source of variability. During meiosis in sexual organisms, two homologous chromosomes one from the male and the other from female parents crossover one another and exchange their genetic material. The chromosomes then split and form an offspring. it can be selected to increase fitness by nature because the more recombination the more variability and the more variability the easier it is for the population to handle the changes. Therefore The most common cause of variations is recombination in the organism.
So, the correct answer is option B, Recombination.

Note: Sexual reproduction increases genetic variation in offspring, which in turn increases the genetic variability in species. Therefore genetic variability depends on sexual reproduction highly.