Ecosystems & Biodiversity is a core part of GCSE Environmental Science. Revise the key concepts and common mistakes below, then lock them in with the free games.
Key concepts
BiodiversityVariety of life across genes, species and ecosystems.
Species RichnessNumber of different species in an area.
Species EvennessHow equally individuals are spread across species.
Indicator SpeciesSpecies whose presence shows environmental conditions.
Keystone SpeciesSpecies with disproportionate impact on its ecosystem.
HabitatPlace where a species naturally lives and grows.
Habitat FragmentationContinuous habitat split into smaller isolated patches.
Wildlife CorridorStrip of habitat linking fragmented patches together.
RewildingRestoring ecosystems by reintroducing keystone species.
Ex situ ConservationProtecting species outside natural habitat, e.g. zoos.
In situ ConservationProtecting species within their natural habitat.
Edge EffectDifferent conditions at habitat boundaries vs interior.
IUCN Red ListGlobal database ranking species extinction risk.
Critically EndangeredIUCN category for extremely high extinction risk.
Common mistakes to avoid
Questions where students often pick the tempting wrong answer — make sure you know the right one:
Is protecting one species enough to save an ecosystem?✗ Yes, saving one species protects everything. ✓ No — ecosystems depend on many interacting species and habitats.
Why does a growing human population strain the environment?✗ It has no effect on the environment. ✓ It increases demand for resources, land and energy, and adds waste/emissions.
Is energy recycled within an ecosystem?✗ Yes, energy cycles round endlessly. ✓ No — energy flows through and is lost as heat; nutrients are recycled.
What does biodiversity measure?✗ Only the number of animals. ✓ The variety of all living things and their genes in an area.
Practise Ecosystems & Biodiversity — free games
Test yourself with these quick revision games for this topic:
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