noun \ˌmak-rō-ˈn(y)ü-klē-əs\
plural mac·ro·nu·clei \-ˌī\ also mac·ro·nu·cle·us·es

Definition of MACRONUCLEUS

: a relatively large densely staining nucleus of most ciliate protozoans that is derived from micronuclei and controls various nonreproductive functions—compare micronucleus
mac·ro·nu·cle·ar \ˌmak-rō-ˈn(y)ü-klē-ər\ adjective

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