Micronucleus

Definition

A micronucleus is a small, extra nucleus found in some unicellular eukaryotic organisms, playing a key role in reproductive and genetic processes. It usually contains a copy of the organism's genome and is involved in processes like conjugation.

5 Must Know Facts For Your Next Test

1. The micronucleus is essential for sexual reproduction in ciliates.
2. During conjugation, the micronucleus undergoes meiosis to produce haploid nuclei.
3. It helps maintain genetic diversity by exchanging genetic material with another cell.
4. Micronuclei are distinct from macronuclei, which control non-reproductive cellular functions.
5. Damage or loss of the micronucleus can severely impact an organism's ability to reproduce.

Review Questions

Related terms

Macronucleus: A larger nucleus that controls everyday cellular functions and expresses genes necessary for cell maintenance.

Conjugation:

A form of sexual reproduction where two cells exchange genetic material through direct contact.

Ciliates:

A group of protozoans characterized by the presence of hair-like organelles called cilia used for movement and feeding.