+20 Questions on Photosynthesis
20 multiple choice questions on Photosynthesis, each numbered and followed by an answer key at the end.
Multiple Choice Questions: Photosynthesis
1. What is the primary purpose of photosynthesis?
A) To release oxygen into the air
B) To produce glucose for energy
C) To absorb carbon dioxide
D) To store chlorophyll in plants
2. Which organelle carries out photosynthesis?
A) Mitochondrion
B) Chloroplast
C) Ribosome
D) Nucleus
3. Which pigment is responsible for capturing light energy?
A) Carotene
B) Melanin
C) Chlorophyll
D) Xanthophyll
4. What gas is taken in during photosynthesis?
A) Oxygen
B) Carbon dioxide
C) Nitrogen
D) Hydrogen
5. What are the end products of photosynthesis?
A) Carbon dioxide and water
B) Glucose and oxygen
C) Oxygen and nitrogen
D) Glucose and carbon dioxide
6. In which part of the plant does most photosynthesis occur?
A) Roots
B) Stems
C) Flowers
D) Leaves
7. The process of photosynthesis primarily uses energy from:
A) Chemical bonds
B) Heat
C) The Sun
D) Electricity
8. The overall equation for photosynthesis is:
A) O₂ + H₂O → C₆H₁₂O₆ + CO₂
B) C₆H₁₂O₆ + O₂ → CO₂ + H₂O
C) CO₂ + H₂O → C₆H₁₂O₆ + O₂
D) CO₂ + O₂ → C₆H₁₂O₆ + H₂O
9. What is the role of water in photosynthesis?
A) It provides carbon
B) It releases oxygen
C) It produces chlorophyll
D) It stores energy
10. What happens to the oxygen produced in photosynthesis?
A) It is absorbed by the plant
B) It is used to make glucose
C) It is released into the atmosphere
D) It is converted to carbon dioxide
11. Which part of the chloroplast contains chlorophyll?
A) Outer membrane
B) Inner membrane
C) Thylakoid membrane
D) Stroma
12. What is the name of the light-independent stage of photosynthesis?
A) Glycolysis
B) Calvin Cycle
C) Krebs Cycle
D) Citric Acid Cycle
13. When does the light-dependent stage of photosynthesis occur?
A) At night
B) During the day
C) Only during winter
D) During cellular respiration
14. Which molecule is fixed during the Calvin Cycle?
A) Oxygen
B) Water
C) Carbon dioxide
D) ATP
15. Where does the Calvin Cycle take place?
A) Thylakoid
B) Cytoplasm
C) Stroma
D) Mitochondria
16. Which of the following is not needed for photosynthesis?
A) Carbon dioxide
B) Light
C) Oxygen
D) Water
17. What is the first step of the light-dependent reaction?
A) Glucose production
B) Water splitting
C) Carbon fixation
D) Oxygen absorption
18. ATP and NADPH are used in which part of photosynthesis?
A) Light-dependent reactions
B) Calvin Cycle
C) Glycolysis
D) Krebs Cycle
19. What happens to glucose produced during photosynthesis?
A) It is excreted
B) It is converted to proteins
C) It is used for energy or stored as starch
D) It is destroyed
20. Which color of light is least effective for photosynthesis?
A) Red
B) Blue
C) Green
D) Violet
Answer Key
1. B – To produce glucose for energy
2. B – Chloroplast
3. C – Chlorophyll
4. B – Carbon dioxide
5. B – Glucose and oxygen
6. D – Leaves
7. C – The Sun
8. C – CO₂ + H₂O → C₆H₁₂O₆ + O₂
9. B – It releases oxygen
10. C – It is released into the atmosphere
11. C – Thylakoid membrane
12. B – Calvin Cycle
13. B – During the day
14. C – Carbon dioxide
15. C – Stroma
16. C – Oxygen
17. B – Water splitting
18. B – Calvin Cycle
19. C – It is used for energy or stored as starch
20. C – Green
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