macronucleus

/mak-roh-noo-klee-uhs, -nyoo-/US // ˌmæk roʊˈnu kli əs, -ˈnyu- //UK // (ˌmækrəʊˈnjuːklɪəs) //

大核,大核细胞,大核数,巨核

Definitions

n.名词 noun

1
Biology.
- : 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.

The macronucleus is usually dorsal, elliptical, and cleft, with one micronucleus attached.
The macronucleus is usually double, rarely single or quadruple, but may occasionally break into numerous smaller pieces.
The macronucleus is horseshoe-shaped or ovoid and is situated in the posterior half of the body.
The macronucleus is spheroidal and placed near the center of the body; a conspicuous micronucleus lies near it.
The macronucleus is globular and central, occasionally band-form and with numerous attached micronuclei.