Which statement accurately describes the relationship between cytokinesis and mitosis?

The answer

The accurate statement is: cytokinesis is the division of the cytoplasm that normally follows mitosis, the division of the nucleus, and together they complete cell division to produce two identical daughter cells.

Mitosis and cytokinesis are two distinct but tightly linked events in the M (mitotic) phase of the cell cycle. Mitosis partitions the duplicated chromosomes into two identical nuclei. Cytokinesis then splits the rest of the cell — the cytoplasm and organelles — so that each new nucleus ends up in its own separate cell. Mitosis handles the nucleus; cytokinesis handles the cell body. Neither alone finishes the job.

How they overlap in timing

Although cytokinesis is often said to "follow" mitosis, the two overlap. In animal cells, the contractile ring that pinches the cell in two typically begins forming during anaphase/telophase, the later stages of mitosis, and completes shortly after mitosis ends. So the cleaner way to say it is: cytokinesis begins in late mitosis and concludes after mitosis is complete. That is why "cytokinesis happens after mitosis" and "cytokinesis overlaps the end of mitosis" are both accepted as correct.

In animal cells cytokinesis forms a cleavage furrow (a contractile ring of actin and myosin). In plant cells, which have rigid walls, a cell plate forms in the middle instead and grows outward into a new wall.

Why the common wrong statements are wrong

• "Cytokinesis is a stage of mitosis." Incorrect. Cytokinesis is a separate process; mitosis is strictly nuclear division (prophase, metaphase, anaphase, telophase). They are grouped together under the M phase but are not the same event.
• "Mitosis divides the cytoplasm and cytokinesis divides the nucleus." This reverses them. Mitosis = nucleus; cytokinesis = cytoplasm.
• "Cytokinesis happens before mitosis." Incorrect — you cannot split the cell body until the two nuclei are being separated. Chromosome duplication happens earlier (S phase of interphase), but the physical splitting of the cell comes after nuclear division.
• "They produce genetically different daughter cells." Incorrect. Mitosis is designed to make two genetically identical cells; that is its defining feature, unlike meiosis.

The bigger picture

Place both in the full cell cycle: interphase (G1, S, G2) grows the cell and copies the DNA, then the M phase (mitosis + cytokinesis) divides it. Mitosis ensures each daughter gets a complete, identical chromosome set; cytokinesis ensures each gets a functional cytoplasm and organelles. Remove cytokinesis and you get a single cell with two nuclei (a binucleate cell), which shows clearly that dividing the nucleus and dividing the cell are two different requirements that must both occur for a true cell division.