What cell structure undergoes the greatest changes in the process of division?

The structure that undergoes the greatest changes in the process of division is the core. The nucleus is the most important structure in the cell, which performs such functions as storage, sale and transmission of hereditary information. It consists of chromatin, karyoplasm (nuclear juice), karyolemma (membrane) and nucleoli. Just the same chromatin undergoes significant changes through the spiralization and despiralization of its form at different stages of division (heterochromatin – spiralized form, euchromatin – despiralized form). It should also be noted that nucleoli disappear and their appearance, cytokinesis (division of the cytoplasm) and other important processes.
It should be said about another structure that is undergoing changes – the cell center, which consists of two centrioles. But compared with the core, this structure undergoes minor metamorphoses.