unit 4 populations & environment - chemstuff · photosynthesis and respiration unit 4...

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