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An oocyte or ovocyte is a female gametocyte or germ cell involved in reproduction. Image File history File links Gray5. ...
This article is about the biological chromosome. ...
A human ovum Sperm cells attempting to fertilize an ovum An ovum (plural ova) is a haploid female reproductive cell or gamete. ...
Medical Subject Headings (MeSH) is a huge controlled vocabulary (or metadata system) for the purpose of indexing journal articles and books in the life sciences. ...
A gametocyte is a eukaryotic germ cell that divides by mitosis into other gametocytes or by meiosis into gametes. ...
A germ cell is a kind of cell that is part of the germline, and is involved in the reproduction of organisms. ...
Biological reproduction is the biological process by which new individual organisms are produced. ...
Formation The formation of an oocyte is called oocytogenesis. Thus, oocytogenesis is a form of gametocytogenesis whose male counterpart is spermatocytogenesis. Oocytogenesis results in the formation of both primary oocytes before birth, and of secondary oocytes after it as part of ovulation. Gametocytogenesis is the creation of gametocytes by mitosis of gametogonia. ...
Spermatocytogenesis is the male form of gametocytogenesis. ...
Ovulation is the process in the menstrual cycle by which a mature ovarian follicle ruptures and discharges an ovum (also known as an oocyte, female gamete, or casually, an egg) that participates in reproduction. ...
- The division of an oogonium by mitosis creates two diploid primary oocytes which are kept in a prolonged prophase I, known as the Dictyate stage, ready to continue meiosis when puberty begins.
- As part of ovulation, primary oocytes undergo the first meiotic division, which sees homologous chromosomes pair during prophase and split from one another during anaphase. This forms one haploid secondary oocyte and the first polar body.
- A second period of arrested development occurs after the first meiotic division forms the secondary oocyte. The egg may be expelled from the ovary in this condition, and in many species, including humans, the second meiotic division is not completed until the egg is fertilized by a sperm.
- The oocyte divides in meiosis II into one ootid and the second polar body. The ootid then differentiates into an ovum.
An oogonium is a female gametogonium. ...
Mitosis divides genetic information during cell division. ...
Ploidy is the number of homologous sets of chromosomes in a biological cell, each set essentially coding for all the biological traits of the organism. ...
The Dictyate stage of meiotic prophase is the prolonged resting phase that is terminated shortly before ovulation. ...
In biology, meiosis is the process that allows one diploid cell to divide in a special way to generate haploid cells in eukaryotes. ...
Puberty refers to the process of physical changes by which a childs body becomes an adult body capable of reproduction. ...
Prophase, with the mitotic spindles stained green and the cell nucleus and chromatin stained blue. ...
A lung cell of a newt during early anaphase of mitosis. ...
Ploidy is the number of homologous sets of chromosomes in a biological cell, each set essentially coding for all the biological traits of the organism. ...
Polar body is a cell structure found inside an ovum. ...
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...
For the article on the figure of speech, see meiosis (figure of speech). ...
An ootid is a female gametid, as opposed to a male spermatid. ...
Cellular differentiation is a concept from developmental biology describing the process by which cells acquire a type. The morphology of a cell may change dramatically during differentiation, but the genetic material remains the same, with few exceptions. ...
A human ovum Sperm cells attempting to fertilize an ovum An ovum (plural ova) is a haploid female reproductive cell or gamete. ...
Characteristics - The secondary oocyte is the largest cell in the body, and in humans is just visible to the naked eye.
- Oocytes are rich in cytoplasm which contains yolk granules to nourish the cell early in development.
- The only normal type of secondary oocyte has sex chromosomes 23,X (where sperm can be 23,X or 23,Y).
Organelles. ...
Abnormalities - If nondisjunction occurs -- that is, if the chromosomes fail to separate properly -- a secondary oocyte may have the wrong number of sex chromosomes, for example 22,X or 24,X. This is the cause of conditions like Down syndrome and Edwards syndrome.
- Some oocytes have multiple nuclei, although it is thought they never mature.
In biology, nondisjunction is the failure of a chromosome to split correctly during meiosis. ...
Trisomy 18 or Edwards Syndrome (named after John H. Edwards who first described the syndrome in 1960) is a genetic disorder. ...
The eukaryotic cell nucleus. ...
Additional images Scheme showing analogies in the process of maturation of the ovum and the development of the spermatids. Image File history File links Gray7. ...
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Resources William K. Purves, Gordon H. Orians, David Sadava, H. Craig Heller, Craig Heller (2003). Life: The Science of Biology(7th ed.), pp. 823–824
See also Polar body is a cell structure found inside an ovum. ...
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