Unlike mitosis, where a diploid cell, for example, divides into two diploid cells (equational division), meiosis is a type of cell division where a diploid cell produces four haploid cells, which is why it is a reductive division.

A fact that reinforces the reductive character of meiosis is that, although it comprises two successive stages of cell division, chromosomes duplicate only once during interphase - a period preceding both mitosis and meiosis. At the beginning of interphase, the chromatin filaments are not duplicated. Later, still in this phase, the duplication occurs, leaving each chromosome with two chromatids.

The various stages of meiosis

The reduction of the chromosomal cell number is an important factor for the conservation of the chromosomal batch of the species, because as meiosis gametes form with half of the chromosomal batch. Upon fertilization, that is, the meeting of two gametes, the number of chromosomes of the species is restored.

We can study meiosis in two steps, separated by a short interval called intercinesis. In each step, we find the phases studied in mitosis, that is, prophase, metaphase, anaphase and telophase.

Let's assume a cell 2n = 2 and then study the major events of meiosis in that cell.