A basil plant is grown in a research cabinet with a lamp initially 24 cm away. Light intensity is the only limiting factor. The rate of photosynthesis is to become one ninth of its original rate.
How far must the lamp travel outwards from its starting position to produce this decrease?
A further 96 cm away from the plant
A further 24 cm away from the plant
A further 48 cm away from the plant
A further 72 cm away from the plant
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.