Describe the levels of organisation found within an ecosystem, starting with the smallest level.
Written & reviewed by James Millett — Biology (Imperial College London), PGCE Science (University of Cambridge).
Model answer (4 marks)
The smallest level is the cell (or organelle/molecule). Cells of the same type group to form tissues. Tissues combine to form organs, and organs make up organ systems/organisms. Organisms of the same species in an area form a population; different populations together form a community; the community plus its non‑living environment is an ecosystem.
Examiner tips
- Use the exact sequence of terms – cell, tissue, organ, organ system/organism, population, community, ecosystem.
- Show the hierarchical order clearly, e.g. by numbering or short phrases.
- Mention the non‑living environment only at the ecosystem stage.
- Keep the answer to 4–5 short sentences to match the 4 marks.
Common mistakes
- Confusing organ with organ system; writing ‘organ system’ before ‘organ’. Omitting the non‑living environment when describing an ecosystem. Using ‘organism’ before ‘organ’ or ‘tissue’.”
Mark scheme (4 marks)
- The smallest level of organisation is the cell (or organelle/molecule accepted as smaller unit)
- Cells of the same type group together to form tissues
- Tissues group together to form organs, and organs group together to form organ systems / organisms
- Organisms of the same species living in the same area form a population; different populations living together form a community; the community together with its non-living environment forms an ecosystem
Key terms in this question
Related
- All Eduqas GCSE Biology revision notes →
- How to answer a "Describe" question →
- Decode the mark scheme abbreviations →