1. plural of micronucleus; small nuclei found in certain single-celled organisms that contain genetic material for reproduction
Usage: biology; technical
2. small fragments of chromosomes or whole chromosomes that are not incorporated into daughter cell nuclei during cell division, used as indicators of genetic damage
Usage: genetics; toxicology

Examples

• The paramecium contains both a macronucleus and several micronuclei.
• Scientists observed micronuclei in the ciliated protozoans under the microscope.
• The micronuclei test is used to assess chromosomal damage in cells.
• Exposure to radiation increased the frequency of micronuclei formation.
• Researchers counted micronuclei to evaluate the genotoxic effects of the chemical.
• The presence of micronuclei indicates potential DNA damage in the tissue sample.