Gametes (sperm and ova) are haploid cells. Meiosis produces haploid gametes (ova or sperm) that contain one set of 23 chromosomes. Both of these gametes are haploid cells. Spermatozoa are the mature male gametes in many sexually reproducing organisms. A numerical hybrid results from the fusion of gametes having different haploid numbers of chromosomes. The meiotic process results in production of haploid promastigote-like gametes. The zygote incorporates genetic material from both gametes. This is a consequence of the fact that gametes from sexually reproducing species are haploid. Individual organisms which produce both male and female gametes are termed hermaphroditic. The smaller, motile gametes are spermatozoa and the larger, non-motile gametes are ova. There, they undergo meiosis, followed by cellular differentiation into mature gametes, either eggs or sperm. Diploids are produced by doubling or fusion of gametes after meiosis. They used cryopreservation of gametes and embryos. Prokaryotes are asexual, reproducing without fusion of gametes. Flowers are usually hermaphroditic, producing both male and female gametes.