A lamp is initially 60 cm from pondweed. Light intensity is the only limiting factor. The student wants the rate of photosynthesis to become four times the original rate.
How far towards the pondweed should the lamp be moved?
45 cm towards the pondweed
30 cm towards the pondweed
40 cm towards the pondweed
15 cm towards the pondweed
87 exam-style questions on Edexcel GCSE Biology 6.1 Photosynthesis, covering 6.1.1 Photosynthetic organisms as producers, 6.1.2a Limiting factors on the rate of photosynthesis, 6.1.2b Interactions of limiting factors on photosynthesis, and 6.1.3 Inverse square law and light intensity. Each one has a worked solution and a mark scheme showing where the marks go.