Photosynthesis and Respiration
Unit 4
Populations & Environment
Practice Exam Questions
[Total 13 marks]
3 The Calvin cycle occurs in the light independent stage in chloroplasts
b) Complete the table below to show three major differences between the Krebs cycle and the Calvin
cycle.
Krebs cycle Calvin cycle
electron
carriers
carbon
dioxide
ATP
[3]
The Calvin cycle occurs in the light independent stage in chloroplasts
(b) State one advantage of reactions occurring in cycles, such as the Krebs cycle and the Calvin
cycle.
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[Total 4 marks]
[Total 6 marks]
[Total 7 marks]
6
Respiration & Photosynthesis Answers and markscheme
2
3 (a)
Krebs cycle Calvin cycle
electron carriers NAD, FAD, NADP;
carbon dioxide produced / released, absorbed / fixed;
ATP produced, used;
3
(b) small quantity of ‘starter’ substance required;
intermediates lead to many other series of reactions;
easy to convert substances;
without using too many enzymes; 1 max
[Total: 4]
6