CAIE A Level Biology 9700 · Photosynthesis
A scientist adds a radioactive carbon atom in a molecule of CO₂ to a suspension of illuminated isolated chloroplasts. Describe the pathway of this carbon atom as it is incorporated into a molecule of triose phosphate (TP) in the Calvin cycle. In your answer, explain the roles of rubisco, ATP, and reduced NADP.
5 marks, so the mark scheme is looking for about 5 separate creditworthy points. Making the same point twice in different words earns it once.
Explain means: Give the reasons or the mechanism: why or how something happens. Link each point to the next with because, so or which means. A list of facts with no links usually loses the reasoning marks.
Written by Markquill to follow the Cambridge International syllabus. Markquill is independent and is not affiliated with or endorsed by Cambridge International.