A population of field voles eats grass. Kestrels feed on the field voles.
The field voles eat 1.80 kg of grass biomass during each of two weeks.
The table shows what happens to some of the grass biomass eaten.
| What happens to the grass biomass | Mass in a mild week in kg | Mass in a colder week in kg |
|---|---|---|
| Not digested and egested | 0.36 | 0.36 |
| Lost as urea | 0.09 | 0.09 |
| Used in respiration | 1.17 | 1.26 |
Calculate the efficiency with which the grass biomass eaten is transferred into new field vole biomass during the colder week.
Explain why the colder conditions change the mass of new field vole biomass. In your answer, refer to the products of respiration.
Predict how this change could affect the biomass of the kestrel population.
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.