Scientists fed two animals and measured what happened to the food each animal ate in one day.
The Table shows the results.
Table
| Locust | Mouse | |
|---|---|---|
| Mass of food eaten in g per day | 1.00 | 5.00 |
| Mass lost in faeces in g per day | 0.60 | 0.75 |
| Mass lost in respiration in g per day | 0.20 | 4.00 |
| Mass lost in urine in g per day | 0.02 | 0.10 |
| Increase in biomass in g per day | 0.18 | 0.15 |
Calculate the efficiency of biomass transfer from the seeds to the mouse.
The locust loses a much larger percentage of the food it eats in its faeces than the mouse.
Suggest why.
Use the Table to explain why the efficiency of biomass transfer to the mouse is lower than to the locust.
Suggest why food chains in which the consumers are mammals usually have fewer trophic levels than food chains in which the consumers are insects.
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.