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macronucleus

[mak-roh-noo-klee-uh s, -nyoo-]
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noun Biology.
  1. the larger of the two types of nuclei occurring in ciliate protozoans, having a multiple set of chromosomes and functioning in cell metabolism and protein synthesis.
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Compare micronucleus.

Origin of macronucleus

From New Latin, dating back to 1890–95; see origin at macro-, nucleus
Related formsmac·ro·nu·cle·ar, adjective
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

Examples from the Web for macronucleus

Historical Examples

  • The macronucleus is spherical and has one micronucleus attached.

    Marine Protozoa from Woods Hole

    Gary N. Calkins

  • The macronucleus is spherical, elongate, band-formed or horseshoe-shaped.

  • Macronucleus central, globular to elongate, sometimes double.

  • The macronucleus is long and band-formed or horseshoe shape.

  • The macronucleus is spherical and usually central in position.


British Dictionary definitions for macronucleus

macronucleus

noun plural -clei (-klɪˌaɪ)
  1. the larger of the two nuclei in ciliated protozoansCompare micronucleus
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Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

macronucleus in Medicine

macronucleus

(măk′rō-nōōklē-əs)
n.
  1. The larger of two nuclei present in ciliate protozoans, which controls the nonreproductive functions of the cell.
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Related formsmac′ro•nucle•ar adj.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.