Oogamy

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Oogamy ("egg fertilization", ancient Greek ᾠόν ō (i) ón "egg", γάμος gámos "marriage, marriage") or oogamy is the union of a larger, immobile gamete (called egg cell or oocyte) with a smaller, mobile one in sexual reproduction Gametes (usually referred to as sperm ). The sperm looks for the egg cell and fertilizes it. The egg cell is referred to as female , the sperm as male . Besides humans, oogamy also occurs in all multicellular animals , land plants ( embryophyta ) and some algae .

A special case of oogamy is the siphonogamy or pollen tube fertilization of the seed plants , in which the sperm cells have no flagella and do not actively swim to the egg cell but are brought to it through the pollen tube .

Related terms are isogamy and anisogamy . Isogamy describes the case in which the gametes cannot be distinguished externally, while in anisogamy they differ in size (female gametes larger than male). Anisogamy and oogamy can be seen as different cases; Anisogamy then describes the case that the gametes of both sexes are flagellated and therefore mobile, but of different sizes. In this sense, Marcus Hartog introduced the terms oogamy, isogamy and anisogamy in 1891. Other authors, however, consider oogamy as an extreme case of anisogamy.

In ethnosociology , isogamy and anisogamy are terms for rules of marriage .

Individual evidence

  1. ^ Joachim W. Kadereit, Christian Körner, Benedikt Kost, Uwe Sonnewald: Strasburger - Textbook of Plant Sciences . Springer, Berlin / Heidelberg 2014, ISBN 978-3-642-54435-4 , pp. 642 , doi : 10.1007 / 978-3-642-54435-4 .
  2. ^ Joachim W. Kadereit, Christian Körner, Benedikt Kost, Uwe Sonnewald: Strasburger - Textbook of Plant Sciences . Springer, Berlin / Heidelberg 2014, ISBN 978-3-642-54435-4 , pp. 572 , doi : 10.1007 / 978-3-642-54435-4 .
  3. ^ Rainer Bergfeld: Sexuality in plants . Ulmer, Stuttgart 1977. p. 16.
  4. ↑ Nature, September 17, 1891, p. 484. ( PDF )
  5. ↑ Dieter Heß: Systematic Botany ( UTB. Volume 2673). Eugen Ulmer, Stuttgart (Hohenheim) 2005, ISBN 3-8252-2673-5 , p. 26.
  6. ↑ Adolf Remane , Volker Storch , Ulrich Welsch : Kurzes Lehrbuch der Zoologie . 5th edition, Gustav Fischer Verlag, Stuttgart 1985, p. 242f.