Questions involving processes in respiration and photosynthesis usually give high marks in the Biology A level AQA unit 4 papers. By understanding and learning key parts of the processes, you can ensure yourself to gain the majority of the marks. This question asks about the light independent stage of photosynthesis which must not get confused with the similarly named light-dependent stage. The light independent stage also named the Calvin cycle is the second of two processes of photosynthesis, using the products of the light dependent reaction to produce substances such as glucose to power the cell. In order to answer this question well, you need a systematic approach. That is describing each step using key words before moving onto the next and not over complicating your answer. For example a model answer would be: RuBP combines with Carbon dioxide, giving two molecules of Glycerate-3-phosphate (GP). NADPH and energy from ATP converts the GP to Triose Phosphate. From here, The Triose Phosphate can be converted to glucose or regenerated to RuBP. This answer is short and to the point but will gain the 6 marks. It describes the overview of the Calvin cycle and provides all the key points for the marks.