Zygote


Zygote

Infobox Embryology
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:"For other meanings see Zygote (disambiguation)."A zygote (from Greek ζυγωτός "zugōtos" "joined" or "yoked", from ζυγοῦν "zugoun" "to join" or "to yoke") [cite web| url=http://www.myetymology.com/english/zygote.html |title=English etymology of zygote |publisher=myetymology.com] is a cell that is the result of fertilization. That is, two haploid cells—usually an ovum from a female and a sperm cell from a male—merge into a single diploid cell called the "zygote" (or "zygocyte").

Variations in different species

Animal zygotes undergo mitotic cell divisions to become a blastocyst then an embryo. A zygote has all of the DNA required to grow into a fetus for birth. Other organisms may undergo meiotic cell division at this time (for more information refer to biological life cycles).

In mammals, fusion of the sperm with the ovacyte occurs in the fallopian tube and the resulting diploid zygote becomes embedded in the uterine wall.cite web| url=http://www.umm.edu/ency/article/002398.htm| title=Fetal development |publisher=University of Maryland Medical Center] In humans, the blastocyst often reaches the uterus in five days. On the sixth day, the blastocyst implants itself into the uterine wall.

Twins

Twins and multiple births can be monozygotic (identical) or dizygotic (fraternal), meaning they arise from one or several (strictly, two) fertilization events. Polyspermic zygotes in mice have been manipulated so as to remove one of the two male pronuclei and made to survive birth. [cite web| url=http://www.ncbi.nlm.nih.gov/pubmed/8671222| title=Birth of normal mice after removal of the supernumerary male pronucleus from polyspermic zygotes |publisher=National Center for Biotechnology Information]

In other species

A biparental zygote is a Chlamydomonas (a kind of algae) zygote that contains chloroplast DNA (cpDNA) from both parents.

References

ee also

* Sexual reproduction
* Zygote intrafallopian transfer
* Twin Zygosity


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Look at other dictionaries:

  • zygote — [ zigɔt ] n. m. • 1913; bot. 1890; du gr. zugôtos « attelé » ♦ Biol. Œuf fécondé, avant la première segmentation. Cellule diploïde des végétaux, résultant de la fusion de deux gamètes. ● zygote nom masculin (grec dzugôtos, attelé) Nom… …   Encyclopédie Universelle

  • Zygote — der Alge Spirogyra sp. (in der Mitte des Bildes) Eine Zygote ist eine Zelle (diploid), die durch Verschmelzung zweier haploider Geschlechtszellen (Gameten) entsteht – meistens aus einer Eizelle (weiblich) und einem Spermium (männlich). Diese… …   Deutsch Wikipedia

  • Zygote — (græsk). Når et æg og en sædcelle sammensmeltes til en diploid celle kaldes det for en zygote. En befrugtet ægcelle kunne man også kalde det. En zygote vil efterfølgende gennemgå celledelinger og blive til et foster …   Danske encyklopædi

  • zygote — zygote. См. зигота. (Источник: «Англо русский толковый словарь генетических терминов». Арефьев В.А., Лисовенко Л.А., Москва: Изд во ВНИРО, 1995 г.) …   Молекулярная биология и генетика. Толковый словарь.

  • Zygote — Zygote, bei der geschlechtlichen Fortpflanzung durch Verschmelzen zweier geschlechtsverschiedener Gameten entstandene Zelle. Aus der Z. entwickelt sich ein neues Individuum …   Deutsch wörterbuch der biologie

  • zygote — (n.) 1880, coined 1878 by German cytologist Eduard Strasburger (1844 1912), the widespread attribution to Mendel being apparently erroneous; from Gk. zygotos yoked, from zygon yoke (see JUGULAR (Cf. jugular)) …   Etymology dictionary

  • zygote — ► NOUN Biology ▪ a cell resulting from the fusion of two gametes. DERIVATIVES zygotic adjective. ORIGIN from Greek zug tos yoked …   English terms dictionary

  • zygote — [zī′gōt΄, zig′ōt΄] n. [< Gr zygōtos, yoked < zygon,YOKE] a diploid cell formed by the union of two haploid gametes, esp. by the union of an egg cell and a sperm cell zygotic [zī gät′ik, zigät′ik] adj. zygotically adv …   English World dictionary

  • Zygote — Œuf (biologie) Pour les articles homonymes, voir Œuf et Zygote (homonymie). Œufs, Adolphe Millot, Nouveau Larousse Illustré, 1897 1904 …   Wikipédia en Français

  • Zygote — befruchtete Eizelle * * * Zy|go|te 〈f. 19〉 bei der Verschmelzung von Geschlechtszellen entstehender organ. Verband [<grch. zygotos „verbunden“ <zygoun „verbinden“; zu zygon „Joch“] * * * Zy|go|te, die; , n [zu griech. zygōtós = durch ein… …   Universal-Lexikon


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