Question

How does meiosis create genetic diversity?

Answer 1

Hint: Basically we have two kinds of cell divisions- mitosis and meiosis. The degree or amount of variation always depends on the type genetic material, the genetic makeup and constitution. The genetic constitution differs in case of mitosis and meiosis.

Complete answer:
To understand the creation of genetic variation among species it is very important to know the types of cell division taking place in species (more specifically in eukaryotes) namely- mitosis and meiosis.

Mitosis: When a cell undergoes mitosis two new cells called daughter cells are formed having the same genetic material as that of the parent cell. The daughter cells resemble the parent cells in every aspect and even in its genetic constitution as they have the same number of chromosomal count. So there is no genetic variation in case of mitosis.

Meiosis: In case of meiosis a particular cell divides to give rise to four daughter cells (because meiosis consists of two cycles-meiosis I and meiosis II) each carrying different constituents of genetic material. The daughter cells contain half the number of chromosomal counts from that of the parent cell. In case of meiosis a phenomenon called ‘Recombination’ takes place in which genetic material gets exchanged between two chromosomes and hence each cell has a different genetic constitution.

Note: The mitosis takes place in somatic cells (i.e. cells other than sperm and ova) and somatic cells are diploid means having two pairs of chromosomes (2n=46, where n=23).
But meiosis takes place in germ cells (i.e. sperm and ova) which contain half set of chromosomes (haploid=23 chromosome) so that when they fertilise, the offspring have 46 chromosomes. And since meiosis takes place in germ cells fusion of which gives birth to new life that leads to genetic variation among species.