The table shows the biomass at each trophic level in a food chain.
Table
| Trophic level | Biomass in g/m2\text{g/m}^2g/m2 |
|---|---|
| Producers | 25000 |
| Primary consumers | 2500 |
| Secondary consumers | 200 |
| Tertiary consumers | 18 |
Between which two trophic levels is the transfer of biomass most efficient?
producers to primary consumers
primary consumers to secondary consumers
secondary consumers to tertiary consumers
the efficiency is the same between all levels
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.