GCSERevise
AQASpec 4.7Foundation & Higher~30 min

Ecology

Biology · Topic revision workspace

Topic progress0%

Read the notes, score 80% and know 75% of the cards.

Topic overview

What you need to know

Ecology is a key part of GCSE Biology. Connect structures to their functions and explain biological processes as clear causal sequences. A community of living organisms (biotic) interacting with their non-living environment (abiotic). All the populations of different species living and interacting in an area. All the organisms of one species living in a habitat.

Exam tip

Use precise scientific vocabulary and make each link in an explanation explicit.

Revision notes

Core ideas

Secure these ideas first. Say each definition in your own words, then connect it to the topic overview.

  • Ecosystem: A community of living organisms (biotic) interacting with their non-living environment (abiotic).
  • Community: All the populations of different species living and interacting in an area.
  • Population: All the organisms of one species living in a habitat.
  • Food Chain: A diagram showing the flow of energy from producer → primary consumer → secondary consumer → tertiary consumer.

Revision notes

Apply it in the exam

The exam will rarely ask for an isolated definition. Practise selecting the right idea and using it as part of a complete explanation or method.

  • Biodiversity: The variety of different species of organisms on Earth or within an ecosystem.
  • Abiotic Factor: A non-living factor that affects an ecosystem, e.g. temperature, light intensity, water availability, soil pH.
  • Biotic Factor: A living factor that affects an ecosystem, e.g. predation, competition, disease, food availability.
  • Quadrat: A square frame (often 0.5m × 0.5m) placed on the ground to sample and estimate the population of organisms in an area.

Core knowledge

Key facts for Ecology

1

Ecosystem

A community of living organisms (biotic) interacting with their non-living environment (abiotic).

2

Community

All the populations of different species living and interacting in an area.

3

Population

All the organisms of one species living in a habitat.

4

Food Chain

A diagram showing the flow of energy from producer → primary consumer → secondary consumer → tertiary consumer.

5

Biodiversity

The variety of different species of organisms on Earth or within an ecosystem.

6

Abiotic Factor

A non-living factor that affects an ecosystem, e.g. temperature, light intensity, water availability, soil pH.

7

Biotic Factor

A living factor that affects an ecosystem, e.g. predation, competition, disease, food availability.

8

Quadrat

A square frame (often 0.5m × 0.5m) placed on the ground to sample and estimate the population of organisms in an area.

Active recall

Close the notes and answer these

  1. 1.Without looking, explain ecosystem and give one example or consequence.
  2. 2.Without looking, explain community and give one example or consequence.
  3. 3.Without looking, explain population and give one example or consequence.
  4. 4.Without looking, explain food chain and give one example or consequence.

Content reviewed 23 July 2026 against the current linked specification.

Finished learning?

Mark the notes complete, then test what you can recall.

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Official AQA specification