Meiosis is a special type of cell division necessary for sexual reproduction in eukaryotes. The cells produced by meiosis are gametes or spores. In many organisms, including all animals and land plants (but not some other groups such as fungi), gametes are called sperm and egg cells. Whilst the process of meiosis bears a number of similarities with the 'life-cycle' cell division process of mitosis, it differs in two important respects: 1. The chromosomes in meiosis undergo a recombination which shuffles the genes producing a different genetic combination in each gamete, compared with the co-existence of each of the two separate pairs of each chromosome (one received from each parent) in each cell which results from mitosis. 2. The outcome of meiosis is four (genetically unique) haploid cells, compared with the two (genetically identical) diploid cells produced from mitosis. With the decrease in the number of chromosomes in meiosis in the life cycle transition from the diploid phase to haploid. Meiosis creates an opportunity for the emergence of new combinations of genes, since the formation of genetically different gametes. Reduction of the number of chromosomes leads to the formation of "pure gametes" carrying only one allele of the corresponding locus.