volvox


volvox
/vol"voks/, n.
any colonial, freshwater green algae of the genus Volvox, forming a hollow, greenish sphere of flagellated cells.
[1790-1800; < NL, equiv. to L volv(ere) to turn, roll + -ox (as in ferox)]

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      genus of freshwater, chlorophyll-containing green algae (division Chlorophyta). The spherical or oval hollow colonies, one cell in depth and sometimes exceeding the size of a pinhead, contain from 500 to 60,000 cells embedded in a gelatinous wall.

      Asexual colonies have biflagellated somatic cells and reproductive cells (gonidia) that produce small daughter colonies within the parent. Developing ova or spermatozoa replace gonidia in sexual colonies. Fertilization of eggs results in zygotes, which encyst and are released from the parent colony after its death. Thick-walled zygotes formed late in the summer serve as winter resting stages.

      Volvox exhibits differentiation between somatic and reproductive cells, a phenomenon considered by some zoologists to be significant in tracing the evolution of higher animals from Protozoa. Certain species, in which somatic cells appear to be joined by cytoplasmic strands, may be considered as multicellular organisms.

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Universalium. 2010.

Look at other dictionaries:

  • Volvox — Fichier:Volvox aureus.jpg Volvox aureus …   Wikipédia en Français

  • Volvox — aureus Systematik ohne Rang: Chloroplastida Abteilung: Chlorophyta …   Deutsch Wikipedia

  • volvox — volvóx s. m. Trimis de siveco, 10.08.2004. Sursa: Dicţionar ortografic  VOLVÓX s.m. Algă verde formată din indivizi flagelaţi, care trăieşte în colonii de formă sferică cu diametru până la un metru. [< fr., lat. volvox]. Trimis de… …   Dicționar Român

  • Volvox — Vol vox, n. (Bot.) A genus of minute, pale green, globular, organisms, about one fiftieth of an inch in diameter, found rolling through water, the motion being produced by minute colorless cilia. It has been considered as belonging to the… …   The Collaborative International Dictionary of English

  • volvox — [väl′väks΄] n. [ModL < L volvere, to roll (see WALK) + ox (as in atrox, fierce)] any of a genus (Volvox, family Volvocaceae) of multicellular, free swimming, flagellated green algae whose cells form a pale green globular colony that rolls… …   English World dictionary

  • Volvox — Volvox, eine Art Infusionsthierchen …   Pierer's Universal-Lexikon

  • Volvox — L. (Kugelalge, Kugeltier), Gattung einzelliger, Chlorophyll führender und daher grün gefärbter, aktiv beweglicher Organismen, die kugelförmige Kolonien (Cönobien) bilden. Die Gattung wird zu den Geißeltierchen (Autoflagellaten), aber auch zu den… …   Meyers Großes Konversations-Lexikon

  • Volvox — L., Algengattg. der Chlorophyzeen, hohlkugelige, aus Tausenden von Einzelzellen bestehende, mittels Zilien bewegliche Kolonien von 0,5 mm Durchmesser; zuzeiten massenhaft in Teichen auftretend, z.B. V. globātor L., früher als Kugeltierchen zum… …   Kleines Konversations-Lexikon

  • volvox — 1798, from L. volvere to roll (see VULVA (Cf. vulva)) …   Etymology dictionary

  • Volvox — carteri …   Wikipédia en Français

  • Volvox — This article is about Volvox, a colony of microorganisms. For the rock music band with the same name, see Volvox (band) Taxobox | name = Volvox image width = 200px image caption = Volvox aureus regnum = Plantae phylum = Chlorophyta classis =… …   Wikipedia


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