Calvin Cycle: Test Questions with Answers
Multiple Choice Questions:
1. Where does the Calvin cycle take place?
A. Cytoplasm
B. Stroma of chloroplasts
C. Mitochondria
D. Thylakoid membrane
Answer: B
2. What is the main purpose of the Calvin cycle?
A. Produce oxygen
B. Convert light energy into chemical energy
C. Synthesize glucose from carbon dioxide
D. Break down glucose
Answer: C
3. Which molecule is fixed in the Calvin cycle?
A. O2
B. H2O
C. CO2
D. Glucose
Answer: C
4. What enzyme catalyzes the first step of the Calvin cycle?
A. ATP synthase
B. Rubisco
C. PEP carboxylase
D. Kinase
Answer: B
5. Which of the following is not a phase of the Calvin cycle?
A. Carbon fixation
B. Reduction
C. Regeneration of RuBP
D. Glycolysis
Answer: D
6. What is the 5-carbon sugar involved in the Calvin cycle?
A. Glucose
B. RuBP
C. G3P
D. PGA
Answer: B
7. How many turns of the Calvin cycle are required to produce one molecule of glucose?
A. 2
B. 3
C. 6
D. 1
Answer: C
8. Which compound is a direct product of the Calvin cycle?
A. Glucose
B. G3P
C. Pyruvate
D. NADPH
Answer: B
9. What energy molecules are used in the Calvin cycle?
A. NADP+ and ATP
B. NADPH and ATP
C. FADH2 and NADH
D. ADP and Pi
Answer: B
10. Which is not required for the Calvin cycle to proceed?
A. CO2
B. NADPH
C. ATP
D. O2
Answer: D
11. The Calvin cycle is part of which process?
A. Cellular respiration
B. Glycolysis
C. Photosynthesis
D. Fermentation
Answer: C
12. How many molecules of G3P are needed to make one glucose?
A. 1
B. 2
C. 3
D. 6
Answer: B
13. What happens during the regeneration phase?
A. Glucose is formed
B. CO2 is fixed
C. RuBP is regenerated
D. Oxygen is released
Answer: C
14. In which organisms does the Calvin cycle occur?
A. Animals only
B. Fungi only
C. Photosynthetic organisms
D. Bacteria only
Answer: C
15. Which of the following is reduced during the Calvin cycle?
A. ATP
B. G3P
C. NADPH
D. 3-PGA
Answer: D
Identification Questions:
16. Identify the enzyme responsible for CO2 fixation in the Calvin cycle.
Answer: Rubisco
17. Identify the cellular compartment where the Calvin cycle takes place.
Answer: Stroma
18. Identify the 3-carbon sugar produced by the Calvin cycle.
Answer: G3P
19. Identify the energy-carrying molecule used in the Calvin cycle.
Answer: ATP
20. Identify the molecule that donates electrons in the Calvin cycle.
Answer: NADPH
21. Identify the 5-carbon molecule that reacts with CO2.
Answer: RuBP
22. Identify the number of carbon atoms in one molecule of glucose.
Answer: 6
23. Identify the total number of ATP molecules needed to produce one glucose.
Answer: 18
24. Identify the total number of NADPH molecules needed to produce one glucose.
Answer: 12
25. Identify the three main phases of the Calvin cycle.
Answer: Carbon fixation, reduction, regeneration
26. Identify the term for the incorporation of CO2 into an organic molecule.
Answer: Carbon fixation
27. Identify the light-independent reactions of photosynthesis.
Answer: Calvin cycle
28. Identify the compound regenerated in the last step of the Calvin cycle.
Answer: RuBP
29. Identify the type of biochemical pathway the Calvin cycle represents.
Answer: Anabolic pathway
30. Identify one environmental factor that affects the Calvin cycle.
Answer: Temperature
