What is Meiosis

Meiosis is a type of cell division which only occurs within the reproductive organs. Meiosis is a two part cell division (meiosis I and meiosis II). Meiosis produces four daughter cells with half the number of chromosomes and thus is a reduction division.


The importance of meiosis

The importance of meiosis is listed below:

Sexual Reproduction

In humans if the sperm cell and egg cell both had 46 chromosomes like other body cells then during fertilisation the fertilised egg would have 92 chromosomes (twice as many as required). However, meiosis produces sperm cells and egg cells which only contain 23 chromosomes allowing the normal number of 46 chromosomes to be restored at fertilisation when a sperm fuses with an ovum.

Genetic Variation

Meiosis allows for new combination of genes to occur in the gametes (cells involved in sexual reproduction). This leads to genetic variation in the offspring.



Where meiosis takes place?

Meiosis occurs during the formation of sperm and egg cells in animals, and during spore formation in plants.

In animals:
The ovaries produce eggs (ova) by meiosis and the testes produce sperm cells by meiosis.

In plants:
The ovaries produce egg cells by meiosis and the anthers produce pollen by meiosis.