A student collects gas from pondweed using a gas syringe. At the same lamp distance, one measurement is much lower than the other measurements. The student finds a loose connection in the apparatus.
What should the student do before calculating a mean?
Double the lowest result and calculate the mean without repeating.
Remove the highest result and calculate the mean without repeating.
Move the lamp closer and repeat the measurement at that distance.
Seal the connection and repeat the measurement at that distance.
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.