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Separate Biology · Paper 2 · Foundation + Higher · B7

Conditions for decomposition

Key ideas1 of 3

Decay depends on living decomposers

Decomposition breaks down dead organisms and waste biological material. Many bacteria and fungi act as decomposers. Their enzymes carry out chemical reactions, so the conditions around them affect how quickly decay happens. Compare equal starting amounts of the same material before judging a rate. A greater mass lost in a fixed time indicates faster decay, provided other causes of mass loss, such as evaporation, are controlled.

Conditions table: A 10 C moist oxygen available; B 25 C moist oxygen available; C 25 C dry oxygen available; D 25 C moist oxygen absent.

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Practice, downloads and sources

Daily 5 · Exam practice · Revision sheet ↓

Foundation + Higher · B7. Use alongside the shared B7 lessons.

AQA GCSE Biology 8461 · 4.7.2.3. Original notes, questions and diagrams. Models are simplified; teaching data are illustrative.