Meiosis is the division of the cell nucleus (usually two successive divisions), which results in the formation of daughter cells with a haploid number of chromosomes, i.e. the number of chromosomes in a cell is halved.
During meiosis, reduction division occurs in which the diploid (2n) mother cell divides into four haploid (n) daughter cells. This process consists of two successive divisions of the cell nucleus - meiosis I and meiosis II.
During meiosis I, conjugation of homologous chromosomes and crossing over occur, resulting in genetic diversity in the daughter cells. Meiosis II is similar to mitosis and leads to the separation of haploid cells.
Thus, thanks to meiosis, sex cells (eggs and sperm) with a haploid set of chromosomes are formed. This is necessary to maintain a constant number of chromosomes during fertilization and ensure genetic diversity in the offspring.