A student places a lamp 10 cm from some pondweed in a beaker of water. The student puts a glass tank of water between the lamp and the beaker. Why does the student do this?
to increase the light intensity reaching the pondweed
to add more carbon dioxide to the water around the pondweed
to stop heat from the lamp changing the temperature of the pondweed
to stop the oxygen made by the pondweed escaping into the air
117 exam-style questions on OCR GCSE Biology 1.4 Photosynthesis, covering 1.4.1 Photosynthesisers as biomass producers, 1.4.2 Factors affecting the rate of photosynthesis, and 1.4.3 Limiting factors in photosynthesis. Each one has a worked solution and a mark scheme showing where the marks go.