Which statement explains why food chains rarely have more than five trophic levels?
Predators at the top eat all of the organisms below, so the chain ends.
Producers cannot make enough glucose to feed more than five consumers.
Each level gains biomass, so the top consumers grow too large to survive.
Biomass is lost at each level, so too little is left for another level.
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.