Mitosis and cytokinesis
Chromosomes condense, spindle microtubules attach to kinetochores, and replicated chromosomes align before sister chromatids separate. Each separated chromatid is then an individual chromosome. A normal mitosis generally preserves the chromosome complement and produces genetically similar daughter nuclei, apart from new mutations. Animal cells divide through a contractile cleavage furrow; plant cells build a cell plate. Cytokinesis failure can leave multiple nuclei in one cell.
MAKE IT CONCRETE
If a cell completes nuclear division but cannot assemble its cleavage furrow, it can become one cell with two nuclei rather than two properly separated cells.
DON’T FALL FOR THIS
Homologous pairs do not normally line up as tetrads in mitosis. That pairing belongs to meiosis I.