Micronucleus vs. Macronucleus

Micronucleusnoun

(biology) A small nucleus.

Micronucleusnoun

(biology) The smaller of the nuclei of a ciliate protozoan (that contains genetic material)

Micronucleus

Micronucleus is the name given to the small nucleus that forms whenever a chromosome or a fragment of a chromosome is not incorporated into one of the daughter nuclei during cell division. It usually is a sign of genotoxic events and chromosomal instability.

Macronucleusnoun

(biology) The larger of the two nuclei present in ciliate protozoans; it controls the nonreproductive functions of the cell.

Macronucleus

A macronucleus (formerly also meganucleus) is the larger type of nucleus in ciliates. Macronuclei are polyploid and undergo direct division without mitosis.