Meiosis is a complex process that occurs in all sexually reproducing organisms. It is a unique cell division that produces haploid gametes from diploid parental cells. During sexual reproduction, the union of two haploid spores restores the diploid chromosome complement of an organism. Thus, meiosis helps maintain chromosome numbers at a constant level from generation to generation, and ensures the operation of Mendel’s laws of heredity. The steps of gametogenesis are premeiotic, meiotic [pairing of homologous chromosomes, assembly of the synaptonemal complex (SC), formation of chiasma (formation of stable connections between homologs formed at the site of crossovers), and recombination and creation of haploid meiotic products], and postmeiotic mitosis (gametophytogenesis — the equational division). The meiotic events are divided into a series of substages based on changes in chromosome morphology (Table 4.1).