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Biology
OCR GCSE Biology A
Community level systems

OCR GCSE Biology A · J247 · Topic B4

Community level systems

Paper 2 (Foundation) or Paper 4 (Higher) · 10 notes

B4.1 Ecosystems

B4.1a Material cycling
B4.1b Role of microorganisms
B4.1c Carbon and water cycles
B4.1d Factors affecting decomposition
B4.1e Levels of organisation
B4.1f Abiotic and biotic factors
B4.1g Interdependence and competition
B4.1h Trophic levels
B4.1i Pyramids of biomass
B4.1j Efficiency of biomass transfer

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