Describe four differences between a prokaryotic cell and a eukaryotic cell.

AQA GCSE Biology (8461) — 4.1.1 Cell structure · Describe · 4 marks · View as Markdown

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

Model answer (4 marks)

1. Prokaryotic cells lack a nucleus, whereas eukaryotic cells have a true nucleus.
2. Prokaryotes contain plasmids – extra‑chromosomal DNA loops in the cytoplasm – which are absent in eukaryotes.
3. Prokaryotic cells are generally smaller (≈0.5–5 µm) than eukaryotic cells (≈10–100 µm).
4. Prokaryotes have no membrane‑bound organelles such as mitochondria or chloroplasts; eukaryotes do.

Examiner tips

Use the exact terms ‘nucleus’, ‘plasmids’, ‘membrane‑bound organelles’. Show each point clearly, numbered or bullet‑pointed. Keep the answer concise – 4 points for 4 marks.

Common mistakes

Confusing ‘plasmids’ with ‘chromosomes’. Writing ‘prokaryotes are larger’ instead of ‘smaller’. Forgetting to mention the absence of a nucleus in prokaryotes.

Mark scheme (4 marks)

A prokaryotic cell does not contain a nucleus / eukaryotic cell contains a nucleus
Prokaryotic cells contain plasmids (loops of DNA in the cytoplasm) / eukaryotic cells do not contain plasmids
Prokaryotic cells are smaller than eukaryotic cells
Prokaryotic cells do not contain membrane-bound organelles (e.g. mitochondria / chloroplasts) / eukaryotic cells contain membrane-bound organelles

Key terms in this question

prokaryotic cell · eukaryotic cell