An ecologist is investigating the factors limiting the distribution of the saltmarsh grass Spartina anglica in a coastal estuary. They record the following parameters at different tidal heights:
Which of the options correctly identifies only the abiotic factors recorded in this investigation?
111, 333, and 444 (soil salinity, frequency of tidal inundation, and grazing intensity)
222 and 444 (interspecific competition and grazing intensity)
111 and 333 (soil salinity and frequency of tidal inundation)
222 and 333 (interspecific competition and frequency of tidal inundation)
67 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.