Biology MYA Complete Practice Test 2026 – Prepare for Your Exam

Nuclear division into two new nuclei happens during mitosis, which is the M phase of the cell cycle. In mitosis the replicated chromosomes condense, align, and are separated, leading to two distinct nuclei in the daughter cells. After mitosis, cytokinesis splits the cytoplasm to form two separate cells. So the division of the nucleus is specifically mitosis. Cytokinesis divides the cytoplasm, not the nucleus; the G2 checkpoint is just a regulatory pause before mitosis; and chromosomes are the genetic material being separated, not a phase.