 A spermatozoon fertilising an ovum Fertilisation, also spelled fertilization (also known as conception, fecundation and syngamy), is fusion of gametes to form a new organism of the same species. In animals, the process involves a sperm fusing with an ovum, which eventually leads to the development of an embryo. Depending on the animal species, the process can occur within the body of the female in internal fertilisation, or outside in the case of external fertilisation. Fertilisation is quite crazy and wacky --86.130.48.105 15:19, 11 October 2006 (UTC)ajones Image File history File links Sperm-egg. ...
Image File history File links Sperm-egg. ...
This is one of a series of articles about the differences between American English and British English, which, for the purposes of these articles, are defined as follows: American English (AmE) is the form of English used in the United States. ...
Gametes, from the ancient Greek γαμετης (spouse), are the specialized germ cells that come together during fertilization (conception) in organisms that reproduce sexually. ...
In biology and ecology, an organism (in Greek organon = instrument) is a living complex adaptive system of organs that influence each other in such a way that they function as a more or less stable whole. ...
In biology, a species is one of the basic units of biodiversity. ...
Phyla Subregnum Parazoa Porifera (sponges) Subregnum Agnotozoa Placozoa (trichoplax) Orthonectida (orthonectids) Rhombozoa (dicyemids) Subregnum Eumetazoa Radiata (unranked) (radial symmetry) Ctenophora (comb jellies) Cnidaria (coral, jellyfish, anemones) Bilateria (unranked) (bilateral symmetry) Acoelomorpha (basal) Myxozoa (slime animals) Superphylum Deuterostomia (blastopore becomes anus) Chordata (vertebrates, etc. ...
The contents of the Sperm article were merged into this article and now redirects here. ...
A human ovum Sperm cells attempting to fertilize an ovum An ovum (plural ova) is a haploid female reproductive cell or gamete. ...
Embryos (and one tadpole) of the wrinkled frog (Rana rugosa). ...
Internal fertilization is a form of animal fertilization of an ovum by spermatozoon within the body of an inseminated animal, whether female or hermaphroditic. ...
External fertilization is a form of fertilization in which a sperm cell is united with an egg cell external to the body of the female. ...
The entire process of development of new individuals is called procreation, the act of species reproduction. Reproduction is the creation of one thing as a copy of, product of, or replacement for a similar thing, e. ...
For other uses, see Reproduction (disambiguation) Reproduction is the biological process by which new individual organisms are produced. ...
Fertilization in plants
After the pistil is pollinated, the pollen grain germinates in a response to a sugary fluid secreted by the mature stigma. From each pollen grain, a pollen tube grows out attempting to travel into the ovary by creating a path. The vegetative and generative nuclei of the pollen grain pass into its respective pollen tube. The growth of the pollen tube is controlled by the vegetative nucleus. Enzymes are secreted to digest the tissue of the stigma as the pollen tube grows. The pollen tube does not directly reach the ovary in a straight line. It travels near the skin of the style and curls to the bottom of the ovary, then near the receptacle, it breaks through the ovule through the microphyle (an opening in the ovule wall) and reaches the ovum to fertilise it. This is the point when fertilisation actually occurs. After being fertilised, the ovary starts to swell and becomes a fruit. hello With multi-seeded fruits, multiple grains of pollen are necessary for syngamy with each ovule. The Pistil is the part of the flower made up of one or more carpels. ...
A flower-fly pollinating a Common Daisy (Bellis perennis) Pollination is an important step in the reproduction of seed plants: the transfer of pollen grains (male gametes) to the plant carpel, the structure that contains the ovule (female gamete). ...
Pollen may refer to the microspores of either angiosperms (flowering plants) or gymnosperms (conifers and cycads). ...
Neuraminidase ribbon diagram An enzyme (in Greek en = in and zyme = blend) is a protein, or protein complex, that catalyzes a chemical reaction and also controls the 3D orientation of the catalyzed substrates. ...
Amaryllis style and stigmas A carpel is the female reproductive organ of a flower; the basic unit of the gynoecium. ...
Category: ...
An ovule is a structure found in seed plants that develops into a seed after fertilization. ...
Fruit stall in Barcelona, Catalonia. ...
The process is easy to visualise if one looks at maize silk, which is the female flower of corn. Pollen from the tassel (the male flower) falls on the sticky external portion of the silk, and then pollen tubes grow down the silk to the attached ovule. The dried silk remains inside the husk of the ear as the seeds mature; if one carefully removes the husk, the floral structures may be shown. The development of the flesh of the fruit is proportional to the percentage of fertilised ovules. For example, with watermelon, about a thousand grains of pollen must be delivered and spread evenly on the three lobes of the stigma to make a normal sized and shaped fruit. Binomial name Zea mays L. Maize (Zea mays ssp. ...
See also: Hilt (band) and Peter Hilt The hilt of a sword is its handle, consisting of a guard, grip and pommel. ...
Binomial name Citrullus lanatus (Thunb. ...
Double fertilization Double fertilisation refers to the process in angiosperms (flowering plants) during reproduction, in which two sperm nuclei from each pollen tube fertilise two cells in an ovary. The pollen grain adheres to the stigma of the carpel (female reproductive structure) and grows a pollen tube that penetrates the ovum through a tiny pore called a micropyle. Two sperm cells are released into the ovary through this tube. One of the two sperm cells fertilises the egg cell (at the end of the ovary), forming a diploid (2n) zygote. The other sperm cell fuses with two haploid polar nuclei in the centre of the embryo sac. The resulting cell is triploid (3n). This triploid cell divides through mitosis and forms the endosperm, a nutrient-rich tissue inside the fruit. Classes Magnoliopsida - Dicots Liliopsida - Monocots The flowering plants (also angiosperms or Magnoliophyta) are one of the major groups of modern plants, comprising those that produce seeds in specialized reproductive organs called flowers, where the ovulary or carpel is enclosed. ...
For other uses, see Reproduction (disambiguation) Reproduction is the biological process by which new individual organisms are produced. ...
The signifier sperm can refer to: (mass noun, from Greek sperma = seed) a substance which consists of spermatozoa and which is a component of semen (mass noun) semen itself (informally, count noun with plural sperm or sperms) a single spermatozoon (= sperm cell) sperma ceti (Latin ceti, genitive of cetus = whale...
Cells in culture, stained for keratin (red) and DNA (green). ...
Longitudinal section of female flower of squash showing ovary, ovules, pistil, and petals In the flowering plants, an ovary is a part of the female reproductive organ of the flower or gynoecium. ...
SEM image of pollen grains from a variety of common plants: sunflower (Helianthus annuus), morning glory (Ipomoea purpurea), hollyhock (Sidalcea malviflora), lily (Lilium auratum), primrose (Oenothera fruticosa), and castor bean (Ricinus communis). ...
Amaryllis style and stigmas A carpel is the female reproductive organ of a flower; the basic unit of the gynoecium. ...
Pollen may refer to the microspores of either angiosperms (flowering plants) or gymnosperms (conifers and cycads). ...
A human ovum Sperm cells attempting to fertilize an ovum An ovum (plural ova) is a haploid female reproductive cell or gamete. ...
Diploid (meaning double in Greek) cells have two copies (homologs) of each chromosome (both sex- and non-sex determining chromosomes), usually one from the mother and one from the father. ...
This article or section does not cite its references or sources. ...
Embryos (and one tadpole) of the wrinkled frog (Rana rugosa). ...
Polyploid (in Greek: πολλαπλόν - multiple) cells or organisms contain more than one copy (ploidy) of their chromosomes. ...
Mitosis is the process by which a cell separates its duplicated genome into two identical halves. ...
Endosperm is a triploid tissue (containing three sets of chromosomes) found in the seeds of flowering plants. ...
// Nutrients and the body A nutrient is any element or compound necessary for or contributing to an organisms metabolism, growth, or other functioning. ...
Biological tissue is a group of cells that perform a similar function. ...
Fruit stall in Barcelona, Catalonia. ...
The two central maternal nuclei that contribute to the endosperm arise by mitosis from a single meiotic product. Therefore, maternal contribution to the genetic constitution of the triploid endosperm is different from that of the embryo.
Recently research has shown that one primitive group of flowering plants, the water lilly, Nuphar, the endosperm is diploid, resulting from the fusion of a pollen nucleus with one, rather than two, maternal nuclei.[1] Species About 10-15 species, including: Nuphar advena Nuphar japonica Nuphar kalmiana Nuphar lutea- Yellow Water-lily Nuphar microphylla Nuphar orbiculata Nuphar polysepala Nuphar pumila- Least Water-lily Nuphar rubrodisca Nuphar saggitifolia Nuphar shimadae Nuphar ulvacea Nuphar variegata Nuphar is genus of aquatic plants in the family Nymphaeaceae, with a...
In gymnosperms, such as conifers, the food storage tissue is part of the female gametophyte, a haploid (1n) tissue, so there is no double fertilisation. Gymnosperms are seed-bearing, vascular plants. ...
// Overview A gametophyte is the haploidor possibly diploid structure or phase of life of a sexually-reproducing plant. ...
Haploid (meaning simple in Greek) cells have only one copy of each chromosome. ...
Fertilization in mammals All mammals rely on internal fertilisation through copulation. To deliver the sperm to the female, the male inserts his sexual organ, the penis, into the opening of the vagina, the passage into the female's other sexual organs. (This process is a part of copulation.) Once the male ejaculates, a large number of sperm cells swim toward the ovum. Orders Subclass Multituberculata (extinct) Plagiaulacida Cimolodonta Subclass Palaeoryctoides (extinct) Subclass Triconodonta (extinct) Subclass Australosphenida Ausktribosphenida Monotremata Subclass Eutheria (excludes extinct ancestors) Afrosoricida Anagaloidea (extinct) Arctostylopida (extinct) Artiodactyla Carnivora Cetacea Chiroptera Cimolesta (extinct) Creodonta (extinct) Condylarthra (extinct) Dermoptera Desmostylia (extinct) Dinocerata (extinct) Embrithopoda (extinct) Hyracoidea Insectivora Lagomorpha Litopterna (extinct) Macroscelidea Mesonychia...
A pair of lions copulating in the Maasai Mara, Kenya. ...
The hand mirror and comb of the Roman Goddess Venus is often used to represent the female sex. ...
The shield and spear of the Roman God Mars are often used to represent the male sex In heterogamous species, male is the sex of an organism, or of a part of an organism, which typically produces smaller, mobile gametes (spermatozoa) that are able to fertilise female gametes (ova). ...
A sex organ, or primary sexual characteristic, narrowly defined, is any of those parts of the body (which are not always bodily organs according to the strict definition) which are involved in sexual reproduction and constitute the reproductive system in an complex organism; namely: Male: penis (notably the glans penis...
The penis (plural penises, penes) is an external male sexual organ. ...
The vagina, (from Latin, literally sheath or scabbard ) is the tubular tract leading from the uterus to the exterior of the body in female placental mammals and marsupials, or to the cloaca in female birds, monotremes, and some reptiles. ...
This article is about male ejaculation. ...
The capacitated spermatozoon and the oocyte meet and interact in the ampulla of the fallopian tube. In mammals, binding of the spermatozoon to the zona pellucida, an extracellular layer surrounding the oocyte, initiates the acrosome reaction. This process releases the enzyme hyaluronidase, which digests the matrix of hyaluronic acid in the vestments surrounding the oocyte. Fusion between the sperm and oocyte plasma membranes follows, allowing the entry of the sperm nucleus, mitochondria, centriole and flagellum into the oocyte. Once the ovum fuses with a single sperm cell, its cell membrane changes, preventing fusion with other sperm. Capacitation refers to the post-ejaculatory process that takes place in mammalian spermatozoa that renders them competent to interact with, and fertilize, an oocyte. ...
Female internal reproductive anatomy The Fallopian tubes or oviducts are two very fine tubes leading from the ovaries of female mammals into the uterus. ...
The zona pellucida is a glycoprotein membrane surrounding the plasma membrane of an oocyte. ...
An oocyte or ovocyte is a female gametocyte or germ cell involved in reproduction. ...
In sperm cells of many higher animals, the acrosome develops over the anterior half of its head. ...
I hate FREEHAND?POWERPOINT!!!!year= 2004|title= Simulations of the large kinetic isotope effect and the temperature dependence of the hydrogen atom transfer in lipoxygenase|journal = J. Am. ...
Hyaluronidase The hyaluronidases (EC 3. ...
Hyaluronan (also called hyaluronic acid or hyaluronate) is a glycosaminoglycan distributed widely throughout connective, epithelial, and neural tissues. ...
Drawing of a cell membrane A component of every biological cell, the cell membrane (or plasma membrane) is a thin and structured bilayer of phospholipid and protein molecules that envelopes the cell. ...
In cell biology, the nucleus (from Latin nucleus or nuculeus, kernel) is found in all eukaryotic cells and contains the nuclear genes which form most of the cells genetic material. ...
Electron micrograph of a mitochondrion showing its mitochondrial matrix and membranes In cell biology, a mitochondrion (plural mitochondria) (from Greek μιτος or mitos, thread + κουδÏιον or khondrion, granule) is an organelle, variants of which are found in most eukaryotic cells. ...
Organelles. ...
A flagellum (plural, flagella) is a whip-like organelle that many unicellular organisms, and some multicellular ones, use to move about. ...
This process ultimately leads to the formation of a diploid cell called a zygote. When the embryo reaches the uterus and implants in the endometrium, it begins to divide and form an embryo. At this point the female is said to be pregnant. If the embryo emplants in the fallopian tubes, rather than in the uterus, an ectopic pregnancy results, which can be fatal to the mother. Diploid (meaning double in Greek) cells have two copies (homologs) of each chromosome (both sex- and non-sex determining chromosomes), usually one from the mother and one from the father. ...
This article or section does not cite its references or sources. ...
The endometrium is the inner uterine membrane in mammals which is developed in preparation for the implantation of a fertilized egg upon its arrival into the uterus. ...
Pregnant woman at 26-week gestation A pregnant woman near the end of her term Pregnancy is the carrying of one or more embryos or fetuses by female mammals, including humans, inside their bodies. ...
In some animals (e.g. rabbit) the act of coitus induces ovulation by stimulating release of the pituitary hormone gonadotropin. This greatly increases the probability that coitus will result in pregnancy.
If fertilisation takes place, the sperm usually meet the ovum in the fallopian tube, requiring the sperm cells to swim from the upper vagina through the cervix and across the length of the uterus before reaching the fallopian tube—a considerable distance compared to the size of the sperm cell. Schematic frontal view of female anatomy The cervix (from Latin neck) is the lower, narrow portion of the uterus where it joins with the top end of the vagina. ...
The uterus or womb is the major female reproductive organ of most mammals, including humans. ...
Human fertilization -
The term "conception" commonly refers to fertilisation, but is sometimes defined as implantation or even "the point at which human life begins" and is thus a subject of semantic arguments within the abortion debate. Gastrulation is the point in development when the implanted blastocyst develops three germ layers, the endoderm, the exoderm and the mesoderm. It is at this point that the genetic code of the father becomes fully involved in the development of the embryo. Until this point in development, twinning is possible. Additionally, interspecies hybrids which have no chance of development survive until gastrulation. However this stance is not entirely warranted since human developmental biology literature refers to the "conceptus" and the medical literature refers to the "products of conception" as the post-implantation embryo and its surrounding membranes.[2] The term "conception" is not usually used in scientific literature because of its variable definition and connotation. Human fertilization is the union of a human egg and sperm, usually occurring in the ampulla of the fallopian tube. ...
Fertilization and genetic recombination Meiosis results in a random segragation of the genes contributed from each parent. Each parent organism generally has the same genetic makeup, but differs for a fraction of their genes. Therefore, each gamete produced a person will be genetically different from the others from that person, as well as from the gametes produced by another person. When gametes first fuse at fertilisation, the chromosomes donated by the parents are combined, and, in humans, this means that (2²²)², chromosomally different zygotes are possible for the non-sex chromosomes, even assuming no chromosomal crossover. If crossover occurs once, then on average (4²²)² genetically different zygotes are possible for every couple, not considering that crossover events can take place at most points along each chromosome. The X and Y chromosomes do not undergo crossover events, so are excluded from the calculation. Note that the mitochondrial DNA is only inherited from the maternal parent. Gametes, from the ancient Greek γαμετης (spouse), are the specialized germ cells that come together during fertilization (conception) in organisms that reproduce sexually. ...
Figure 1: Chromosome. ...
A parent is a father or mother; one who begets or one who gives birth to or nurtures and raises a child; a relative who plays the role of guardian // Mother This article or section does not cite its references or sources. ...
Trinomial name Homo sapiens sapiens Linnaeus, 1758 Humans, or human beings, are bipedal primates belonging to the mammalian species Homo sapiens (Latin for wise man or knowing man) under the family Hominidae (known as the great apes). ...
This article or section does not cite its references or sources. ...
Thomas Hunt Morgans illustration of crossing over (1916) Homologous Recombination is the process by which two chromosomes, paired up during prophase I of meiosis, exchange some distal portion of their DNA. Crossover occurs when two chromosomes, normally two homologous instances of the same chromosome, break and then reconnect but...
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See also In vitro fertilization (IVF) is a technique in which egg cells are fertilized outside the mothers body in cases where conception is difficult or impossible through normal intercourse. ...
Fetal (U.S. English; Foetal UK English) development is the process in which a fetus (U.S. English; Foetus UK English) develops during gestation, from the times of conception until birth. ...
Superfetation (also spelt superfoetation, based on a false etymology — see fetus) is the formation of a fetus while another fetus is already present in the uterus. ...
Superfecundation is the fertilisation of two or more ova from the same cycle by sperm from separate acts of sexual intercourse. ...
Notes and references - ^ Friedman, W. E. & J. H. Williams (2003). Modularity of the angiosperm female gametophyte and its bearing on the early evolution of endosperm in flowering plants. Evolution 57 (2): 216-30.
- ^ Moore, K. L. & T. V. M. Persaud (2003). The Developing Human: Clinically Oriented Embryology. W. B. Saunders Company. ISBN 0721669743.
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