Scientists gave a plant water containing a type of oxygen atom that can be traced. The carbon dioxide given to the plant contained only normal oxygen atoms. The traced oxygen atoms were found in the oxygen gas released by the plant. Which conclusion is supported by this evidence?
The oxygen gas released comes from water split in the first stage.
The oxygen gas released comes from carbon dioxide in the second stage.
The oxygen gas released comes from glucose broken down in respiration.
The oxygen gas released comes from water made in the second stage.
117 exam-style questions on OCR GCSE Biology 1.4 Photosynthesis, covering 1.4.1 Photosynthesisers as biomass producers, 1.4.2 Factors affecting the rate of photosynthesis, and 1.4.3 Limiting factors in photosynthesis. Each one has a worked solution and a mark scheme showing where the marks go.