macronucleus

[ mak-roh-noo-klee-uhs, -nyoo- ]

noun

, Biology.

1. the larger of the two types of nuclei nucleus occurring in ciliate protozoans, having a multiple set of chromosomes and functioning in cell metabolism and protein synthesis.

macronucleus

/ ˌmækrəʊˈnjuːklɪəs /

noun

1. See micronucleus
   the larger of the two nuclei in ciliated protozoans Compare micronucleus

Other Words From

• macro·nucle·ar adjective

Word History and Origins

Origin of macronucleus¹

From New Latin, dating back to 1890–95; macro-, nucleus

Example Sentences

The macronucleus is usually dorsal, elliptical, and cleft, with one micronucleus attached.

From Project Gutenberg

The macronucleus is usually double, rarely single or quadruple, but may occasionally break into numerous smaller pieces.

From Project Gutenberg

The macronucleus is horseshoe-shaped or ovoid and is situated in the posterior half of the body.

From Project Gutenberg

The macronucleus is spheroidal and placed near the center of the body; a conspicuous micronucleus lies near it.

From Project Gutenberg

The macronucleus is globular and central, occasionally band-form and with numerous attached micronuclei.

From Project Gutenberg