Definitions for macronucleusˌmæk roʊˈnu kli əs, -ˈnyu-

This page provides all possible meanings and translations of the word macronucleus

WiktionaryRate this definition:(0.00 / 0 votes)

  1. macronucleus(Noun)

    The larger the two nuclei present in ciliate protozoans; it controls the nonreproductive functions of the cell.

FreebaseRate this definition:(0.00 / 0 votes)

  1. Macronucleus

    A macronucleus is the larger type of nucleus in ciliates. Macronuclei are polyploid and undergo direct division without mitosis. It controls the non-reproductive cell functions, the everyday tasks, such as metabolism. During conjugation, the macronucleus disintegrates, and a new macronucleus is formed by karyogamy of the micronuclei. The macronucleus contains hundreds of chromosomes, each present in many copies. The macronucleus lacks a mechanism to precisely partition this complex genome equally during nuclear division; thus how the cell manages to maintain a balanced genome after generations of divisions is a mystery.

U.S. National Library of MedicineRate this definition:(0.00 / 0 votes)

  1. Macronucleus

    The larger of two types of nuclei in ciliate protozoans. It is the transcriptionally active nucleus of the vegetative cells as distinguished from the smaller transcriptionally inert GERMLINE MICRONUCLEUS.


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