Describe the cell cycle and explain why mitosis is important in multicellular organisms.

WJEC A-Level Biology (Wales) — 1.6 Cell division · Describe and Explain · 5 marks · View as Markdown

Written & reviewed by James Millett — Biology (Imperial College London), PGCE Science (University of Cambridge).

Model answer (5 marks)

The cell cycle is a series of events that take place in a cell in preparation for cell division.

During interphase the cell grows, the number of organelles increases and the DNA is replicated.

Mitosis then occurs, producing two daughter cells each with an identical set of chromosomes, so each daughter cell is genetically identical to the parent.

Mitosis is important for growth of the organism, allowing cells to increase in number.

It is also essential for replacing old or damaged cells and for repairing tissues.

Examiner tips

  • Use the exact wording from the mark scheme – e.g. ‘cell cycle’, ‘interphase’, ‘mitosis’, ‘identical copies of DNA’.
  • Show the sequence: interphase → mitosis, and link mitosis to growth and repair.
  • Keep the answer concise – one sentence per point.
  • Use UK spelling (e.g. ‘organelles’).

Common mistakes

  • Confusing meiosis with mitosis; describing meiosis instead of mitosis.
  • Omitting the replication of DNA during interphase.
  • Using vague terms like ‘cell division’ without specifying mitosis.

Mark scheme (5 marks)

  1. The cell cycle is a series of events that take place in a cell in preparation for cell division
  2. During interphase, DNA is replicated and the cell grows / number of organelles increases
  3. Mitosis produces two daughter cells, each with identical copies of DNA / identical to the parent cell
  4. Mitosis is important for growth of the organism
  5. Mitosis is important to replace old or damaged cells / repair tissues

Key terms in this question

cell cycle · mitosis

Related

More Cell division questions

▶ Try answering this question with AI marking (free) →