D2.1.2—Cytokinesis

Cytokinesis divides cytoplasm after nuclear division, using cleavage furrows in animal cells and cell plates in plant cells during division.

Syllabus
First assessment 2025
Objective
D2.1.2
Level
HL

Exam analysis

Chance of appearing2%of analysed past papers
Latest appearanceNovember 2025
Most common paperPaper1A
Typical marks1–8

Common command terms

  • Compare
  • Explain

Scoring notes

Common mistake
Confusing cytokinesis with mitosis instead of separating cytoplasmic division from nuclear division.

Recent exam appearances

November 2025Paper1A ["HL"] · TZ119[ 1 ]D2.1.2—Cytokinesis
May 2025Paper2 ["HL"] · TZ28(c)[ 8 ]D2.1.2—Cytokinesis
Practice this objective

Coverage 2025–2025 · Updated 16 Jul 2026

Cytokinesis Separates the Cytoplasm

Cytokinesis splits the cytoplasm of a parent cell between its daughter cells, but animal and plant cells achieve the split differently.

Cell type Cytokinesis mechanism
Animal A contractile ring of actin and myosin tightens, pulling the plasma membrane inward to form a cleavage furrow
Plant Vesicles fuse at the centre to build new membrane; their contents contribute to a cell plate and new cell wall

An animal cell pinches from its outer edge toward the centre, whereas a plant cell builds the separating plate from the centre outward.

Cytokinesis divides cytoplasm; mitosis or meiosis divides the nucleus. The events can overlap in time but are not the same process.

Cytokinesis exam focus

Assessment in practice

1–8 marks
How it is assessed

This objective is assessed through structured response, commonly using Compare / Explain.

Command terms

Compare / Explain

What earns marks

Build the answer around this relationship: Cytokinesis separates cytoplasm to complete cell division.

Watch for

Confusing cytokinesis with mitosis instead of separating cytoplasmic division from nuclear division.

Representative question

Question 1

[Maximum number: 8]

Compare and contrast the processes of mitosis and cytokinesis in animal and plant cells.

Core Cell Division

  • Cell division produces daughter cells for growth, repair or reproduction; cytokinesis divides cytoplasm by a contractile ring in animals or a cell plate in plants.
  • DNA replication creates sister chromatids joined at centromeres before nuclear division.
  • Mitosis preserves chromosome number: chromosomes condense, align, sister chromatids separate and nuclei reform, producing genetically identical nuclei.
  • Meiosis follows one replication with two divisions: homologous chromosomes separate in meiosis I and sister chromatids in meiosis II, producing haploid cells.
  • Crossing over, independent orientation and random fertilization generate allele combinations.
  • Non-disjunction is failed chromosome separation and can produce aneuploid cells, including trisomy 21.
  • Identify stages in micrographs from chromosome condensation, equatorial alignment, separation and nuclear-envelope cues.

Concept essentials

  • Cytokinesis separates cytoplasm to complete cell division.
  • Animal cells divide cytoplasm by an actin-myosin contractile ring.
  • Plant cells form a vesicle-derived cell plate and new wall.
  • Cytokinesis follows nuclear division to produce separate daughter cells.