has characteristic capable of capable of gamete haploid nucleated cell FMA:18649 CALOHA:TS-0395 haploid germ cell Gametes are reproductive cells essential for sexual reproduction in eukaryotic organisms, including humans, animals, and many plants. These cells are haploid, containing half the genome or only one set of chromosomes, which is a contrast to the diploid state (two sets of chromosomes) found in most cells in a multicellular organism. This reduction in genetic material is crucial since it allows for the re-establishment of the diploid number of chromosomes when two gametes merge to form a diploid zygote during fertilization. There are two major types of gametes in animals: sperm cells in males and egg (or ova) in females. These gametes contribute equally to the genetic makeup of the offspring but are morphologically and functionally distinct. Sperm cells (or spermatozoa) are characterized by their motility, small size, and large quantities; they are produced continuously in vast numbers through a process called spermatogenesis in the male gonads or testes. Female gametes are much larger, fewer in numbers, and are not motile; they undergo a development process known as oogenesis, which takes place within the ovaries. The egg also contributes most of the cytoplasm and organelles (including mitochondria) to the zygote that are required for initial cell division stages after fertilization. Gametes have a primary role in sexual reproduction and genetic variation, which aids in evolution. The formation of gametes involves a special type of cell division called meiosis that introduces genetic diversity via the process of recombination and independent assortment. Following the fusion of male and female gametes, the combination of paternal and maternal genetic material in the zygote allows for genetic recombination, which is a fundamental source of genetic variation and, thus, evolution. Therefore, gametes not only are critical to the inception of new individuals but also contribute to species survival and evolution. (This extended description was generated by ChatGPT and reviewed by the CellGuide team, who added references, and by the CL editors, who approved it for inclusion in CL. It may contain information that applies only to some subtypes and species, and so should not be considered definitional.) FBbt:00005412 ZFA:0009156 A mature sexual reproductive cell having a single set of unpaired chromosomes. https://cellxgene.cziscience.com/cellguide/CL_0000300 haploid cell germ cell fertilization haploid