Why do karyokinesis and cytokinesis occur?
Karyokinesis and cytokinesis are involved in the splitting of a cell during cellular reproduction. Cytokinesis (“moving of the cytoplasm”) occurs during telophase when the cytoskeleton pulls the plasma membrane inward around the equator of the cell, pinching off two portions of the cytoplasm into two daughter cells. Karyokinesis (“moving of the nucleus”) occurs before cytokinesis. I believe it’s the dismantaling of the nuclear envelope so the DNA can finish being sorted into chromosomes (late prophase, or prometaphase) and line up at the equator (metaphase) of the cell in preparation for being separated into sister chromatids (anaphase) by the opposite centrioles at either pole of the cell. After the cell splits, the “piles” of genetic material are gathered up and new nuclear envelopes are built around them in either daughter cell.
