The division of the nucleus of a cell is called mitosis.

Here's why:

* Mitosis is the process where a single cell divides into two identical daughter cells.

* This process includes the division of the nucleus (karyokinesis) and the division of the cytoplasm (cytokinesis).

While meiosis also involves nuclear division, it's the process that produces gametes (sperm and egg cells) which have half the number of chromosomes as the parent cell.