What is significance of meiosis?

1 Answer

Meiosis provides the correct amount of chromosomes in each cell for sexual reproduction. It also provides genetic recombination through crossing over .


All of your regular body cells, or DIPLOID somatic cells, have 46 chromosomes in them. Half of that is from your mother, or "maternal", and half of from your father, or "paternal". Meiosis and subsequent fertilisation made this possible.

Meiosis takes a diploid cell, (a cell containing 46 chromosomes in case of human), and splits it into four cells that are haploid, or contain half the chromosomes. Sex cells, or gametes, have half the regular amount of chromosomes, so each gamete has 23 chromosomes in humans. This is possible through meiosis.

Here is one of the best sites I have found to explain it:

Mitosis vs Meiosis explanation

It only shows Meiosis in males, though it occurs in females as well. The only difference is that in females, four cells are produced, but all of the nutrients and organelles go to one egg, and the other three die. This is to help provide nutrients and energy for the future embryo.

When sexual reproduction occurs, the two haploid cells meet and the nucleus of the sperm goes into the cytoplasm of the egg. The two haploid nuclei fuse and a diploid zygote (=first cell of embryo) is formed. Mitosis then occurs repeatedly for further development of embryo.

Meiosis provides a mixture of DNA from your maternal grandparents through your mother and also from your paternal grandparents through your father, to provide more genetic diversity and therefore a better chance of survival in case of living organisms. This is achieved by crossing over, an exchange of chromosomal parts that takes place during meiosis.

Moreover, meiosis maintains diploid chromosome number through generations by reducing the chromosome number to half in each gamete.