macronuclear
Macronuclear is a term used in biology, specifically in the study of protozoa, to refer to the larger of the two types of nuclei found in ciliates. Ciliates are a group of single-celled eukaryotes that possess two distinct types of nuclei. The macronucleus is a highly polyploid nucleus, meaning it contains many copies of the genome. It is essential for the day-to-day metabolic functions and growth of the cell. The macronucleus is typically spherical or kidney-shaped and is responsible for regulating gene expression and protein synthesis. Unlike the micronucleus, the macronucleus does not undergo meiosis or mitosis in the traditional sense during cell division. Instead, it divides amitotically, meaning it elongates and splits into two roughly equal parts.
The origin of the macronucleus is from the micronucleus during the process of sexual reproduction in ciliates,