micronucleus

American  

[mahy-kroh-noo-klee-uhs, -nyoo-] / ˌmaɪ kroʊˈnu kli əs, -ˈnyu- /

noun

Biology.

plural

micronuclei

1. the smaller of the two types of nuclei occurring in ciliate protozoans.

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micronucleus British  

/ ˌmaɪkrəʊˈnjuːklɪəs /

noun

1. the smaller of two nuclei in ciliated protozoans, involved in reproduction Compare macronucleus

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Other Word Forms

• micronuclear adjective

Etymology

Origin of micronucleus

First recorded in 1890–95; micro- + nucleus

Example Sentences

If the algorithm detects a cell with a micronucleus, it sends the location to the microscope.

From Science Daily • Mar. 10, 2026

When a micronucleus ruptures, the chromosome inside is left exposed.

From Science Daily • Feb. 16, 2026

Two rounds of cell division result in four daughter cell per each parent cell, each with one macronucleus and one micronucleus.

From Textbooks • Jan. 1, 2015

The micronucleus undergoes three rounds of mitosis, resulting in eight micronuclei.

From Textbooks • Jan. 1, 2015

The contractile vacuole is central and dorsal; the macronucleus is in the anterior half of the body, with one attached micronucleus.

From Marine Protozoa from Woods Hole Bulletin of the United States Fish Commission 21:415-468, 1901 by Calkins, Gary N. (Gary Nathan)