A student grew seedlings in a transparent chamber under a lamp that emitted only wavelengths absorbed by chlorophyll. A light sensor placed directly behind one leaf detected some of the lamp light. During the investigation, the carbon dioxide concentration in the chamber decreased. The increase in the dry biomass of the seedlings was small.
Suggest how the light detected by the sensor and the fall in carbon dioxide concentration could each account for the small increase in biomass.
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.