A student placed a piece of pondweed 40 cm from a lamp. The pondweed released 3 bubbles per minute.
The student then moved the lamp to 10 cm from the pondweed.
Calculate how many times greater the light intensity is at 10 cm than at 40 cm.
Predict the number of bubbles per minute at 10 cm if light intensity is the only limiting factor.
The pondweed actually released 20 bubbles per minute at 10 cm.
Explain why.
Describe how the student could find out whether carbon dioxide concentration was limiting the rate of photosynthesis at 10 cm.
44 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.