[mak-roh-noo-klee-uh s, -nyoo-]
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.
Origin of macronucleus
Related formsmac·ro·nu·cle·ar, adjective
From New Latin,
dating back to 1890–95;
see origin at macro-
Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
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Historical Examples of macronucleus
British Dictionary definitions for macronucleus
noun plural -clei (-klɪˌaɪ)
the larger of the two nuclei in ciliated protozoansCompare micronucleus
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
Related formsmac′ro•nu′cle•ar adj.
The larger of two nuclei present in ciliate protozoans, which controls the nonreproductive functions of the cell.
The American Heritage® Stedman's Medical Dictionary
Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.