1. What is respiration in plants?
A. Making food
B. Breaking down food to release energy
C. Absorbing water
D. Transpiration
Answer: B
2. The main gas taken in during respiration is:
A. Nitrogen
B. Oxygen
C. Carbon dioxide
D. Hydrogen
Answer: B
3. The gas released during plant respiration is:
A. Oxygen
B. Nitrogen
C. Carbon dioxide
D. Helium
Answer: C
4. Respiration occurs in:
A. Leaves only
B. Roots only
C. Flowers only
D. All living cells
Answer: D
5. The cell organelle responsible for respiration is:
A. Nucleus
B. Ribosome
C. Mitochondria
D. Chloroplast
Answer: C
6. The process of breaking glucose into pyruvate is called:
A. Photosynthesis
B. Glycolysis
C. Transpiration
D. Fermentation
Answer: B
7. Glycolysis occurs in the:
A. Nucleus
B. Cytoplasm
C. Mitochondria
D. Chloroplast
Answer: B
8. Aerobic respiration requires:
A. Sunlight
B. Water
C. Oxygen
D. Carbon dioxide
Answer: C
9. Anaerobic respiration in plants produces:
A. Lactic acid
B. Ethanol and carbon dioxide
C. Oxygen
D. Water only
Answer: B
10. The energy currency of the cell is:
A. DNA
B. ATP
C. RNA
D. ADP
Answer: B
11. The complete breakdown of glucose occurs in:
A. Aerobic respiration
B. Anaerobic respiration
C. Transpiration
D. Photosynthesis
Answer: A
12. Stomata help in:
A. Water absorption
B. Gas exchange
C. Food storage
D. Photosynthesis only
Answer: B
13. Lenticles are involved in:
A. Water transport
B. Gas exchange in stems
C. Photosynthesis
D. Seed formation
Answer: B
14. The first stage of aerobic respiration is:
A. Krebs cycle
B. Electron transport chain
C. Glycolysis
D. Fermentation
Answer: C
15. The Krebs cycle occurs in:
A. Cytoplasm
B. Mitochondrial matrix
C. Nucleus
D. Vacuole
Answer: B
16. Energy released during respiration is stored in the form of:
A. Glucose
B. ATP
C. Oxygen
D. Carbon dioxide
Answer: B
17. Respiration in plants occurs:
A. Only during day
B. Only during night
C. Both day and night
D. Only in sunlight
Answer: C
18. The respiratory quotient (RQ) is:
A. CO₂ released / O₂ consumed
B. O₂ released / CO₂ consumed
C. ATP formed / glucose used
D. Water produced / oxygen used
Answer: A
19. The RQ for carbohydrates is usually:
A. 0.5
B. 1
C. 2
D. 0
Answer: B
20. Which substrate gives RQ less than 1?
A. Carbohydrates
B. Fats
C. Organic acids
D. Glucose
Answer: B
21. The site of electron transport chain is:
A. Cytoplasm
B. Outer mitochondrial membrane
C. Inner mitochondrial membrane
D. Nucleus
Answer: C
22. Fermentation in plants occurs in:
A. Presence of oxygen
B. Absence of oxygen
C. Sunlight only
D. High temperature only
Answer: B
23. The end product of glycolysis is:
A. Lactic acid
B. Ethanol
C. Pyruvic acid
D. Oxygen
Answer: C
24. Which of the following releases the highest energy?
A. Aerobic respiration
B. Anaerobic respiration
C. Fermentation
D. Transpiration
Answer: A
25. Which structure allows gas exchange in roots?
A. Stomata
B. Lenticels
C. Root hairs
D. Cuticle
Answer: C
26. The main respiratory substrate in plants is:
A. Protein
B. Fat
C. Glucose
D. Minerals
Answer: C
27. ATP stands for:
A. Adenosine Triphosphate
B. Adenine Diphosphate
C. Adenosine Diphosphate
D. Adenine Triphosphate
Answer: A
28. During respiration, energy is released in:
A. One step
B. Two steps
C. Several controlled steps
D. No steps
Answer: C
29. The process common to both aerobic and anaerobic respiration is:
A. Krebs cycle
B. Electron transport chain
C. Glycolysis
D. Photosynthesis
Answer: C
30. Respiration is an example of:
A. Anabolic process
B. Catabolic process
C. Synthetic process
D. Constructive metabolism
Answer: B