All of the decomposers in an area of woodland are killed by a chemical.
Which statement describes what would happen in the woodland?
Dead material would build up and mineral ions would not be returned, so plants would grow less.
Dead material would disappear faster and more carbon dioxide would be released, so plants would grow more.
Dead material would build up and more nitrates would be added to the soil, so plants would grow more.
Dead material would build up but carbon dioxide levels would rise, so plants would grow less.
111 exam-style questions on OCR GCSE Biology 4.1 Ecosystems, covering 4.1.1 Cycling of materials in ecosystems, 4.1.2 Microorganisms in cycling materials, 4.1.3 The carbon and water cycles, 4.1.4 Factors affecting decomposition, 4.1.5 Levels of organisation in an ecosystem, 4.1.6 Abiotic and biotic factors affecting communities, 4.1.7 Interdependence and competition, 4.1.8 Trophic levels, 4.1.9 Pyramids of biomass, and 4.1.10 Efficiency of biomass transfers. Each one has a worked solution and a mark scheme showing where the marks go.