Two leaves have the same area and the same number of chloroplasts. Leaf P has large internal air spaces and thin mesophyll cell walls. Leaf Q has smaller air spaces and thicker mesophyll cell walls.
Which statement explains why carbon dioxide can reach chloroplasts more readily in leaf P?
Gas is produced in the spaces and is absorbed by active transport.
Gas is produced in the spaces and diffuses across thinner walls.
Gas moves through the spaces and diffuses across thinner walls.
Gas moves through the spaces and is absorbed by active transport.
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.