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Sperm

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	Topics Sperm Topic Home The term sperm is derived from the Greek word (sp??µa) sperma (meaning "seed") and refers to the male reproductive cells. Sperm cells are the smaller gameteGamete Gametes, from the ancient Greek ?aet?? , are the specialized germ cells that come together during fertilization in orga... s involved in fertilizationFertilization Fertilization , is fusion of gametes to produce a new organism of the same species.... in anisogamyAnisogamy Anisogamy refers to a form of sexual reproduction involving gametes of different sizes.... and oogamyOogamy Oogamy is a form of heterogamy in which the female produced gamete is significantly larger than the male gamete.... . In these types of sexual reproductionSexual reproduction Sexual reproduction is a type of reproduction that results in increasing genetic diversity of the offspring.... , there is a marked difference in the size of the gametes with the smaller one being termed the "male" or sperm cell. The human sperm cell is a haploid, so that its 23 chromosomes can join the 23 chromosomes of the female egg to form a diploid cell. A uniflagellar sperm cell that is motile is also referred to as spermatozoonSpermatozoon A spermatozoon or spermatozoan , from the ancient Greek spe?a and ??? and more commonly known as a sperm ... , whereas a non-motile sperm cell is referred to as spermatium. Sperm cells cannot divide and have a limited life span, but they can fuse with egg cellsOvum An ovum is a haploid female reproductive cell or gamete.... during fertilization to form a totipotentTotipotency Totipotency is the ability of a single cell, usually a stem cell, to divide and produce all the differentiated cells in an o... zygoteZygote A zygote is a cell that is the result of fertilization.... with the potential to develop into a new organism. Mammalian sperm cells can live for up to 3 days inside the female unless it is exposed to air or is mixed with another liquid. The spermatozoa of animals are produced through spermatogenesisSpermatogenesis Overview Spermatogenesis is the process by which stem cells develop into mature spermatozoon cells.... inside the male gonadGonad The gonad is the organ that makes gametes.... s through meiosisMeiosis In biology, meiosis is the process that allows one diploid cell to divide in a special way to generate haploid cells in euka... . Sperm cells in algal and many plant gametophyteGametophyte In plants that undergo alternation of generations, a gametophyte is the structure, or phase of life, that contains only half... s are produced in male gametangia through mitosisMitosis Mitosis is the process by which a cell separates its duplicated genome into two identical halves.... . In flowering plantFlowering plant The flowering plants are a major group of land plants.... s, sperm nuclei are produced inside pollenPollen Pollen, sometimes incorrectly called flower sperm, is a fine to coarse powder consisting of *microgametophytes* ... . Anatomy The sperm cell consists of a head, a midpiece and a tail. The head is the nucleusNucleus Summary Nucleus usually refers to the center of something, but can mean:... with densely coiled cromatinfibres, surrounded anteriorly by an acrosomeAcrosome In spermatozoa of many animals, the acrosome is an organelle that develops over the anterior half of the spermatozoon's head... , which contains enzymes used for penetrating the female egg. The midpiece has a central filamentous core with many mitochondria spiralled around it, used for ATP production for the journey through the female cervixCervix The cervix is the lower, narrow portion of the uterus where it joins with the top end of the vagina.... , uterusUterus The uterus or womb is the major female reproductive organ of most mammals, including humans.... and uterine tubes. The tail or "flagellumFlagellum A flagellum ' is a whip-like organelle that many unicellular organisms, and some multicellular ones, use to move about.... " executes the lashing movements that propel the spermatocyte, and it consists of microtubules in an extension of the cell membrane. Motile sperm cells Motile sperm cells typically move via flagellaFlagellum A flagellum ' is a whip-like organelle that many unicellular organisms, and some multicellular ones, use to move about.... and require water in order to swim toward the egg for fertilization. The uniflagellated sperm cells (with one flagellum) produced in most animalAnimal Animals are a major group of organisms, classified as the kingdom Animalia or Metazoa.... s are referred to as spermatozoaSpermatozoon A spermatozoon or spermatozoan , from the ancient Greek spe?a and ??? and more commonly known as a sperm ... , and are known to vary in size. Motile sperm are also produced by many protistProtist Overview Protists are a heterogeneous group of organisms, comprising those eukaryotes that are not animals, plants, or fungi.... s and the gametophyteGametophyte In plants that undergo alternation of generations, a gametophyte is the structure, or phase of life, that contains only half... s of bryophyteBryophyte The bryophytes are those embryophyte plants that are non-vascular: they have tissues and enclosed reproductive systems, but ... s, fernFern A fern is any one of a group of about 20,000 species of plants classified in the phylum or division Pteridophyta, also... s and some gymnospermGymnosperm Overview Gymnosperms are a group of seed-bearing plants which bear seeds on cone-like structures rather than inside fruit like angios... s such as cycadCycad Cycads are an ancient group of seed plants characterized by a large crown of compound leaves and a stout trunk.... s and ginkgoGinkgo The Ginkgo , frequently misspelled as "Gingko", and sometimes known as the Maidenhair Tree, is a unique tree with no c... . The sperm cells are the only flagellated cells in the life cycle of these plants. In many ferns and lycophytes, they are multi-flagellated (carrying more than one flagellum). In nematodeNematode The nematodes or roundworms are one of the most common phyla of animals, with over 20,000 different described species... s, the sperm cells are amoeboidAmoeboid Amoeboids are cells that move or feed by means of temporary projections, called pseudopods .... and crawl, rather than swim, towards the egg cell. Non-motile sperm cells Non-motile sperm cells called spermatia lack flagella and therefore cannot swim. Spermatia are produced in a spermatangium. Because spermatia cannot swim,they depend on their environment to carry them to the egg cell. Some red algae, such as PolysiphoniaPolysiphonia *Polysiphonia* is a genus of red algae with about 19 species on the coasts of the British Isles and about 200 specie... , produce non-motile spermatia that are spread by water currents after their release. The spermatia of rust fungiRust (fungus) Rusts are fungi of the order Uredinales.... are covered with a sticky substance. They are produced in flask-shaped structures containing nectar, which attract fliesFly This article is about the insect. For other meanings, see Fly ... that transfer the spermatia to nearby hyphae for fertilization in a mechanism similar to insect pollination in flowering plantFlowering plant The flowering plants are a major group of land plants.... s. Fungal spermatia (also called pycnidiospores) may be confused with conidiaConidium *Conidia, or conidiospores, are asexual, non-motile spores of a fungus; they are also called mitospores* due t... . Conidia are sporeSpore In biology, a spore is a reproductive structure that is adapted for dispersion and surviving for extended periods of time in... s that germinate independently of fertilization, whereas spermatia are gameteGamete Gametes, from the ancient Greek ?aet?? , are the specialized germ cells that come together during fertilization in orga... s that are required for fertilization. In some fungi, such as Neurospora crassaNeurospora crassa Neurospora crassa is a type of red bread mold of the phylum Ascomycota.... , spermatia are identical with microconidia as they can perform both functions of fertilization as well as giving rise to new organisms without fertilization. Sperm nuclei In many land plants, including most gymnosperms and all angiosperms, the male gametophyteGametophyte In plants that undergo alternation of generations, a gametophyte is the structure, or phase of life, that contains only half... s are the primary mode of dispersalBiological dispersal Biological dispersal refers to those processes by which a species maintains or expands the distribution of a population.... , for example via wind or insect pollinationPollination Pollination is an important step in the reproduction of seed plants: the transfer of pollen grains to the plant carpel, the ... , eliminating the need for water to bridge the gap between male and female. Each pollen grain contains a spermatogenous (generative) cell. Once the pollen lands on the stigma of a receptive flower, it germinates and starts growing a pollen tubeFacts About Pollen tube Pollen may refer to the microspores of either angiosperms or gymnosperms.... through the carpelCarpel A carpel is the female reproductive organ of a flower; the basic unit of the *gynoecium.... . Before the tube reaches the ovuleOvule An ovule* is a structure found in seed plants that develops into a seed after fertilization.... , the nucleus of the generative cell in the pollen grain divides and gives rise to two sperm nuclei which are then discharged through the tube into the ovuleOvule An ovule is a structure found in seed plants that develops into a seed after fertilization.... for fertilization. In some protistProtist Protists are a heterogeneous group of organisms, comprising those eukaryotes that are not animals, plants, or fungi.... s, fertilization also involves sperm nucleiCell nucleus In cell biology, the nucleus is an organelle found in most eukaryotic cells.... , rather than cells, migrating toward the egg cell through a fertilization tube. Oomycetes form sperm nuclei in a syncyticalSyncytium In biology, a syncytium is a large region of cytoplasm that contains many nuclei.... antheridiumAntheridium An antheridium is a structure or organ of the gametophyte phase of certain plants producing and containing the spermatids or... surrounding the egg cells. The sperm nuclei reach the eggs through fertilization tubes, similar to the pollen tube mechanism in plants. Sperm quality A study by the University of CaliforniaUniversity of California The University of California is a public university system in the state of California.... has suggested that folate may protect sperm cells from aneuploidyAneuploidy Aneuploidy is a condition in which the number of chromosomes is abnormal due to extra or missing chromosomes, in other words... . Market On the global market, DenmarkDenmark The Kingdom of Denmark is the smallest and southernmost of the Nordic countries.... has a well developed system of sperm export. This success mainly comes from the reputation of Danish sperm donors for being of high quality and, in contrast with the law in the other Nordic countries, gives donors the choice to remain anonymous to the receiving couple. More than 50 countries worldwide are importers, including Paraguay, the US, Kenya and Hong Kong. See also EjaculationEjaculation Ejaculation is the process of ejecting semen from the penis, and is usually accompanied by orgasm as a result of sexual stim... Female spermFemale sperm Female sperm is a term that traditionally refers to a sperm that contains an X chromosome produced, in the usual way by a m... PolyspermyPolyspermy In biology, polyspermy describes an egg that has been fertilized by more than one sperm.... SemenSemen Semen is an organic fluid that usually contains spermatozoa.... Sperm competitionSperm competition Sperm competition is "competition between sperm of two or more males for the fertilization of an ova".... Sperm donationSperm donation Sperm donation is the practice by which a man gives or more commonly sells his semen to be used specifically to produce a ba...