macronucleus

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Related to macronuclei: macronuclear, Meganucleus

mac·ro·nu·cle·us

(mak'rō-nū'klē-ŭs),
1. A nucleus that occupies a relatively large portion of the cell, or the larger nucleus where two or more are present in a cell.
See also: micronucleus (2). Synonym(s): meganucleus
2. The larger of the two nuclei in ciliates, which governs vegetative metabolic functions and not reproduction.
See also: micronucleus (2). Synonym(s): somatic nucleus, trophic nucleus, trophonucleus

macronucleus

(măk′rō-no͞o′klē-əs, -nyo͞o′-)
n. pl. macronu·clei (-klē-ī′)
The larger of two nuclei present in ciliate protozoans, which controls nonreproductive functions of the cell, such as metabolism.

mac′ro·nu′cle·ar adj.

mac·ro·nu·cle·us

(mak'rō-nū'klē-ŭs)
1. A nucleus that occupies a relatively large portion of the cell, or the larger nucleus where two or more are present in a cell.
2. The larger of the two nuclei in ciliates, which governs vegetative metabolic functions and not reproduction.
See also: micronucleus (2)

macronucleus

or

meganucleus

the larger of two nuclei found in some PROTOZOANS, that is concerned with cell division (see MICRONUCLEUS). It disappears during CONJUGATION and is afterwards reformed from material of micronuclear origin (from the zygote nucleus). It appears to have mainly vegetative functions.
References in periodicals archive ?
Atypical cells with pleomorphic macronuclei with dense chromatin forming irregular glandular structure are found in the superficial layer (a: red square, d: x20).
Most skin metastases will show a "bottom heavy" growth of the tumor that is restricted to the deep dermis Metastases of colonic origin however may show abutment of the dermis with macronuclei. The presence of goblet cells and intraglandular neutrophils with adenocarcinoma may further suggest a colonic source.
Paramecia can expose students to many organelles that they wouldn't normally have the opportunity to see, such as oral grooves, food vacuoles, cilia, macronuclei, and, in some cases, trichocysts.
They explain laboratory techniques for investigating such topics as genetic processes, mating types, microneuclei and macronuclei, cortical morphogenesis, and behavior.