A student examining cells under a microscope observes that one cell has a nucleus, mitochondria, ribosomes, a cell membrane and a cell wall, but no chloroplasts and no permanent vacuole. State what type of organism this cell is most likely from, and explain how each of the three structural features — cell wall, absence of chloroplasts, and absence of a permanent vacuole — supports this identification.

Pearson Edexcel International GCSE Biology (4BI1) — 2.2 Cell structure · Explain · 4 marks · View as Markdown

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

Model answer (4 marks)

The cell is most likely from a fungus.
1. Cell wall – fungal cell walls are made of chitin, not cellulose, which is typical of plant cells.
2. Absence of chloroplasts – fungi are heterotrophic and do not photosynthesise, so they lack chloroplasts.
3. No permanent vacuole – fungal cells do not have a large central vacuole for storage or structural support as plant cells do.

Examiner tips

  • State the organism first (fungus).
  • Explain each feature in a separate sentence, using the exact terminology (chitin, heterotrophic, no permanent vacuole).
  • Link each feature directly to the identification.

Common mistakes

  • Confusing plant with fungal cell wall composition (cellulose vs chitin).
  • Forgetting to mention that fungi are heterotrophic and lack chloroplasts.

Mark scheme (4 marks)

  1. The cell is most likely from a fungus (fungal cell).
  2. The cell wall is made of chitin (not cellulose), which is characteristic of fungi rather than plants.
  3. Chloroplasts are absent because fungi do not photosynthesise / fungi are not autotrophs and obtain nutrients by absorption.
  4. No permanent vacuole is present because fungi do not store cell sap or use a vacuole for structural support in the way plant cells do.

Key terms in this question

cell wall · chloroplast · vacuole

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