Two food chains in a coastal dune begin with the same biomass of marram grass.
Food chain P: marram grass → grasshopper → lizard → kestrel
Food chain Q: marram grass → vole → kestrel
At every step in both food chains, the same percentage of biomass is transferred and the rest is lost.
Which statement best explains why food chain Q could support a greater biomass of kestrels than food chain P?
Food chain Q has fewer transfers, so less of the marram grass biomass is lost before it reaches the kestrels.
Kestrels in food chain Q are at a higher trophic level, so more biomass is available to them.
Voles egest less biomass in faeces than grasshoppers do, so more biomass reaches the kestrels.
Kestrels in food chain Q are apex predators, so less of their biomass is lost to other consumers.
103 exam-style questions on AQA GCSE Biology 7.4 Trophic levels in an ecosystem, covering 7.4.1 Trophic levels, 7.4.2 Pyramids of biomass, and 7.4.3 Transfer of biomass. Each one has a worked solution and a mark scheme showing where the marks go.