micronucleus: meaning, definition, pronunciation and examples
Very lowScientific / Technical
Quick answer
What does “micronucleus” mean?
A small, distinct nucleus found in some single-celled organisms or a small, extra nucleus-like structure formed from chromosome fragments in a cell.
Audio
Pronunciation
Definition
Meaning and Definition
A small, distinct nucleus found in some single-celled organisms or a small, extra nucleus-like structure formed from chromosome fragments in a cell.
In genetics and toxicology, a small, membrane-bound structure separate from the main nucleus that contains damaged or lagging chromosomal material (e.g., acentric fragments, whole chromosomes) not incorporated into daughter nuclei after cell division; used as a biomarker for genotoxic damage.
Dialectal Variation
British vs American Usage
Differences
No significant spelling or definition differences. Pronunciation differs slightly (see IPA).
Connotations
Identical technical connotations in both varieties.
Frequency
Extremely rare outside specialised biological, genetic, or toxicological contexts in both regions.
Grammar
How to Use “micronucleus” in a Sentence
The chemical induced micronuclei in the lymphocytes.Researchers scored cells for the presence of a micronucleus.A micronucleus formed from the acentric fragment.Vocabulary
Collocations
Examples
Examples of “micronucleus” in a Sentence
verb
British English
- The treatment caused the cells to micronucleate.
- We observed cells micronucleating after exposure.
American English
- The compound micronucleated a significant portion of the cell population.
adverb
British English
- None standard.
American English
- None standard.
adjective
British English
- The micronucleus assay is standard.
- Micronucleus frequency was elevated.
American English
- The micronucleus test results were conclusive.
- Micronucleus formation is a key endpoint.
Usage
Meaning in Context
Business
Not used.
Academic
Used exclusively in biological, genetic, toxicological, and medical research papers and textbooks.
Everyday
Virtually never used.
Technical
Core term in genetic toxicology (e.g., OECD Test Guideline 487) and protozoan biology.
Vocabulary
Synonyms of “micronucleus”
Strong
Neutral
Weak
Vocabulary
Antonyms of “micronucleus”
Watch out
Common Mistakes When Using “micronucleus”
- Misspelling as 'micornucleus' or 'micronucleous'.
- Using plural 'micronucleuses' instead of correct Latin plural 'micronuclei'.
- Confusing it with 'macronucleus' in protozoology.
FAQ
Frequently Asked Questions
No, it is a highly specialised term used almost exclusively in genetics, toxicology, and cell biology.
In ciliate protozoa, the macronucleus controls everyday cell functions, while the smaller micronucleus is involved in genetic reproduction. In genetic toxicology, the macronucleus is the main nucleus, and a micronucleus is a separate, abnormal structure containing genetic damage.
In very specialised technical writing, the back-formation 'to micronucleate' is sometimes used to mean 'to form micronuclei'. It is not standard in general English.
It is a quick, reliable, and internationally standardised (OECD) method to screen chemicals, pharmaceuticals, and environmental samples for their potential to cause genetic damage that may lead to cancer or heritable mutations.
A small, distinct nucleus found in some single-celled organisms or a small, extra nucleus-like structure formed from chromosome fragments in a cell.
Micronucleus is usually scientific / technical in register.
Micronucleus: in British English it is pronounced /ˌmaɪ.krəʊˈnjuː.klɪ.əs/, and in American English it is pronounced /ˌmaɪ.kroʊˈnuː.kli.əs/. Tap the audio buttons above to hear it.
Phrases
Idioms & Phrases
- “None”
Learning
Memory Aids
Mnemonic
Think of a MICROscope focused on a tiny, extra NUCLEUS (micronucleus) floating beside the main one, indicating microscopic damage.
Conceptual Metaphor
A DETOUR or DEAD END for genetic material – chromosomes that got lost and didn't reach their proper destination (the main nucleus).
Practice
Quiz
What is the primary application of the micronucleus test?