RESPIRATION IN PLANTS BEST 100 MCQS| NEET PRACTICE

RESPIRATION IN PLANTS BEST 100 MCQS| NEET PRACTICE| NEET MOCK TEST.

RESPIRATION IN PLANTS:

These questions cover various aspects of plant respiration, including glycolysis, Krebs cycle, electron transport chain, and fermentation. Each answer is followed by a brief explanation to aid in understanding.

Certainly! Here are 100 multiple choice questions on respiration in plants along with answers and explanations:

1. Which of the following is NOT a product of plant respiration?
A) Carbon dioxide
B) Oxygen
C) Glucose
D) Water
*Answer: C) Glucose*
Explanation: Glucose is a substrate for respiration, not a product.

2. Where does the process of respiration primarily occur in plants?
A) Stomata
B) Chloroplasts
C) Mitochondria
D) Vacuoles
*Answer: C) Mitochondria*
Explanation: Mitochondria are the site of cellular respiration in plants.

3. During respiration, oxygen is used for the breakdown of:
A) Starch
B) Glucose
C) Cellulose
D) Sucrose
*Answer: B) Glucose*
Explanation: Glucose is broken down during respiration to release energy.

4. The by product of aerobic respiration in plants is:
A) Carbon dioxide and water
B) Oxygen and glucose
C) Nitrogen and hydrogen
D) Water and sunlight
*Answer: A) Carbon dioxide and water*
Explanation: Aerobic respiration produces carbon dioxide and water.

5. Which type of respiration occurs in the absence of oxygen?
A) Aerobic respiration
B) Anaerobic respiration
C) Photosynthesis
D) Transpiration
*Answer: B) Anaerobic respiration*
Explanation: Anaerobic respiration occurs without oxygen.

6. Which of the following is a product of anaerobic respiration in plants?
A) Oxygen
B) Glucose
C) Carbon dioxide
D) Ethanol
*Answer: D) Ethanol*
Explanation: Ethanol is produced during anaerobic respiration in plants.

7. In plants, the breakdown of glucose during respiration produces:
A) Light energy
B) Chemical energy
C) Heat energy
D) Sound energy
*Answer: B) Chemical energy*
Explanation: Glucose is broken down to release chemical energy in the form of ATP.

8. The energy released during respiration is stored in the form of:
A) Glucose
B) ATP (Adenosine Triphosphate)
C) Starch
D) Cellulose
*Answer: B) ATP (Adenosine Triphosphate)*
Explanation: ATP is the energy currency of the cell and is produced during respiration.

9. During which phase of respiration is the majority of ATP generated in plants?
A) Glycolysis
B) Krebs cycle
C) Electron transport chain
D) Fermentation
*Answer: C) Electron transport chain*
Explanation: The electron transport chain is where most ATP is produced.

10. Which process involves the exchange of gases between plant cells and the atmosphere?
A) Photosynthesis
B) Transpiration
C) Respiration
D) Absorption
*Answer: C) Respiration*
Explanation: Respiration involves the exchange of gases, primarily oxygen and carbon dioxide.

11. Which of the following is NOT a stage of cellular respiration?
A) Glycolysis
B) Krebs cycle
C) Calvin cycle
D) Electron transport chain
*Answer: C) Calvin cycle*
Explanation: The Calvin cycle is part of photosynthesis, not respiration.

12. The net gain of ATP molecules produced during glycolysis is:
A) 2 ATP
B) 4 ATP
C) 36 ATP
D) 38 ATP
*Answer: A) 2 ATP*
Explanation: Glycolysis produces a net gain of 2 ATP molecules.

13. The end product of glycolysis is:
A) Pyruvate
B) Glucose
C) ATP
D) Acetyl CoA
*Answer: A) Pyruvate*
Explanation: Glycolysis ends with the formation of pyruvate molecules.

14. Where does glycolysis occur within plant cells?
A) Chloroplasts
B) Mitochondria
C) Cytoplasm
D) Vacuoles
*Answer: C) Cytoplasm*
Explanation: Glycolysis occurs in the cytoplasm of plant cells.

15. The conversion of pyruvate to acetyl CoA occurs in the:
A) Cytoplasm
B) Chloroplasts
C) Mitochondrial matrix
D) Thylakoid membrane
*Answer: C) Mitochondrial matrix*
Explanation: Pyruvate is converted to acetyl CoA in the mitochondrial matrix.

16. Which of the following is NOT a substrate for the Krebs cycle?
A) Acetyl CoA
B) Pyruvate
C) Glucose
D) Citrate
*Answer: C) Glucose*
Explanation: Glucose is broken down to produce pyruvate, which then enters the Krebs cycle.

17. The Krebs cycle primarily occurs in the:
A) Cytoplasm
B) Mitochondrial matrix
C) Thylakoid membrane
D) Stroma
*Answer: B) Mitochondrial matrix*
Explanation: The Krebs cycle occurs in the mitochondrial matrix.

18. The electron transport chain is located in the:
A) Cytoplasm
B) Mitochondrial matrix
C) Thylakoid membrane
D) Inner mitochondrial membrane
*Answer: D) Inner mitochondrial membrane*
Explanation: The electron transport chain is embedded in the inner mitochondrial membrane.

19. During the electron transport chain, electrons are passed from:
A) NADH to FADH2
B) FADH2 to oxygen
C) NADH to oxygen
D) Oxygen to ATP
*Answer: C) NADH to oxygen*
Explanation: Electrons are passed from NADH to oxygen via a series of electron carriers.

20. The final electron acceptor in the electron transport chain is:
A) NADH
B) FADH2
C) Oxygen
D) Carbon dioxide
*Answer: C) Oxygen*
Explanation: Oxygen is the final electron acceptor, forming water.

21. In the absence of oxygen, what process follows glycolysis?
A) Krebs cycle
B) Fermentation
C) Electron transport chain
D) Calvin cycle
*Answer: B) Fermentation*
Explanation: Fermentation occurs in the absence of oxygen to regenerate NAD+ for glycolysis.

22. Which type of fermentation occurs in plant cells?
A) Alcoholic fermentation
B) Lactic acid fermentation
C) Acetic acid fermentation
D) Butyric acid fermentation
*Answer: A) Alcoholic fermentation*
Explanation: Plant cells typically undergo alcoholic fermentation.

23. The primary purpose of fermentation is to:
A) Produce ATP
B) Produce carbon dioxide
C) Regenerate NAD+
D) Convert glucose to pyruvate
*Answer: C) Regenerate NAD+*
Explanation: Fermentation regenerates NAD+ for glycolysis to continue.

24. How does respiration differ from photosynthesis in terms of energy flow?
A) Respiration releases energy stored in glucose, while photosynthesis requires energy input.
B) Respiration requires energy input, while photosynthesis releases stored energy.
C) Respiration and photosynthesis both release energy stored in glucose.
D) Respiration and photosynthesis both require energy input.
*Answer: A) Respiration releases energy stored in glucose, while photosynthesis requires energy input.*
Explanation: Respiration releases energy stored in glucose, while photosynthesis requires energy input to produce glucose.

25. The overall equation for respiration in plants is the reverse of which process?
A) Photosynthesis
B) Transpiration
C) Fermentation
D) Absorption
*Answer: A) Photosynthesis*
Explanation: Respiration is the reverse process of photosynthesis.

26. In which part of the plant does gas exchange primarily occur?
A) Roots
B) Stem
C) Leaves
D) Flowers
*Answer: C) Leaves*
Explanation: Gas exchange primarily occurs through stomata in leaves.

27. Which of the following is NOT a factor affecting the rate of plant respiration?
A) Temperature
B) Light intensity
C) Oxygen concentration
D) Water availability
*Answer: B) Light intensity*
Explanation: Light intensity primarily affects photosynthesis, not respiration.

28. Which type of respiration occurs during prolonged periods of low oxygen availability?
A) Aerobic respiration
B) Anaerobic respiration
C) Photosynthesis
D) Transpiration
*Answer: B) Anaerobic respiration*
Explanation: Anaerobic respiration occurs in the absence of oxygen.

29. Which of the following is NOT a product of anaerobic respiration in plants?
A) Ethanol
B) Lactic acid
C) Carbon dioxide
D) Oxygen
*Answer: D) Oxygen*
Explanation: Oxygen is not produced during anaerobic respiration.

30. The breakdown of pyruvate during anaerobic respiration leads to the production of:
A) Ethanol
B) Lactic acid
C) Carbon dioxide
D) Oxygen
*Answer: A) Ethanol*
Explanation: Pyruvate is converted to ethanol during anaerobic respiration in plants.

31. Which process occurs simultaneously with respiration in plant cells?
A) Photosynthesis
B) Transpiration
C) Absorption
D) Excretion
*Answer: A) Photosynthesis*
Explanation: Photosynthesis and respiration often occur simultaneously in plant cells.

32. The breakdown of glucose during respiration releases energy in the form of:
A) Glucose
B) Oxygen
C) ATP
D) Carbon dioxide
*Answer: C) ATP*
Explanation: ATP is the primary form of energy released during respiration.

33. The enzyme responsible for catalyzing the breakdown of glucose during glycolysis is:
A) ATP synthase
B) Rubisco
C) Hexokinase
D) Pyruvate kinase
*Answer: C) Hexokinase*
Explanation: Hexokinase catalyzes the initial step of glycolysis.

34. How many carbon atoms are there in pyruvate?
A) 2
B) 3
C) 4
D) 6
*Answer: B) 3*
Explanation: Pyruvate has three carbon atoms.

35. Which of the following molecules is NOT generated during the Krebs cycle?
A) ATP
B) NADH
C) FADH2
D) CO2
*Answer: A) ATP*
Explanation: ATP is not directly generated in the Krebs cycle; it is produced in the electron transport chain.

36. The conversion of pyruvate to acetyl CoA requires the presence of:
A) Oxygen
B) Carbon dioxide
C) Water
D) NADH
*Answer: A) Oxygen*
Explanation: Oxygen is required indirectly because acetyl CoA formation occurs within mitochondria where oxygen is present.

37. During the Krebs cycle, citrate is converted back into which molecule?
A) Oxaloacetate
B) Pyruvate
C) Acetyl CoA
D) Succinate
*Answer: A) Oxaloacetate*
Explanation: Citrate is eventually converted back into oxaloacetate to continue the cycle.

38. Which of the following is a product of the electron transport chain?
A) NAD+
B) FAD
C) ATP
D) Pyruvate
*Answer: C) ATP*
Explanation: The electron transport chain generates ATP from ADP and inorganic phosphate.

39. The movement of protons across the inner mitochondrial membrane drives the synthesis of:
A) Oxygen
B) Carbon dioxide
C) ATP
D) Glucose
*Answer: C) ATP*
Explanation: The movement of protons powers ATP synthase to produce ATP.

40. What is the purpose of the oxygen in the electron transport chain?
A) To accept electrons and form water
B) To release energy
C) To combine with glucose
D) To produce ATP
*Answer: A) To accept electrons and form water*
Explanation: Oxygen is the final electron acceptor, forming water.

41. Which of the following is NOT a step in the process of aerobic respiration?
A) Glycolysis
B) Fermentation
C) Krebs cycle
D) Electron transport chain
*Answer: B) Fermentation*
Explanation: Fermentation is an anaerobic process.

42. In which cellular compartment does the Krebs cycle occur?
A) Cytoplasm
B) Mitochondrial matrix
C) Chloroplasts
D) Endoplasmic reticulum
*Answer: B) Mitochondrial matrix*
Explanation: The Krebs cycle occurs in the mitochondrial matrix.

43. Which of the following is a characteristic of anaerobic respiration?
A) Produces more ATP than aerobic respiration
B) Produces carbon dioxide and water
C) Occurs in the absence of oxygen
D) Takes place in mitochondria
*Answer: C) Occurs in the absence of oxygen*
Explanation: Anaerobic respiration occurs in the absence of oxygen.

44. The primary purpose of the electron transport chain is to:
A) Generate ATP
B) Convert glucose to pyruvate
C) Produce carbon dioxide
D) Break down lipids
*Answer: A) Generate ATP*
Explanation: The electron transport chain generates ATP from the energy of electrons.

45. Which of the following is NOT a product of glycolysis?
A) ATP
B) Pyruvate
C) NADH
D) Carbon dioxide
*Answer: D) Carbon dioxide*
Explanation: Glycolysis does not produce carbon dioxide.

46. Which type of respiration occurs in the absence of oxygen?
A) Aerobic respiration
B) Anaerobic respiration
C) Photosynthesis
D) Transpiration
*Answer: B) Anaerobic respiration*
Explanation: Anaerobic respiration occurs without oxygen.

47. The final electron acceptor in the electron transport chain is:
A) NADH
B) FADH2
C) Oxygen
D) Carbon dioxide
*Answer: C) Oxygen*
Explanation: Oxygen is the final electron acceptor, forming water.

48. The breakdown of glucose during respiration releases energy in the form of:
A) Glucose
B) Oxygen
C) ATP
D) Carbon dioxide
*Answer: C) ATP*
Explanation: ATP is the primary form of energy released during respiration.

49. The enzyme responsible for catalyzing the breakdown of glucose during glycolysis is:
A) ATP synthase
B) Rubisco
C) Hexokinase
D) Pyruvate kinase
*Answer: C) Hexokinase*
Explanation: Hexokinase catalyzes the initial step of glycolysis.

50. How many carbon atoms are there in pyruvate?
A) 2
B) 3
C) 4
D) 6
*Answer: B) 3*
Explanation: Pyruvate has three carbon atoms.

51. Which of the following molecules is NOT generated during the Krebs cycle?
A) ATP
B) NADH
C) FADH2
D) CO2
*Answer: A) ATP*
Explanation: ATP is not directly generated in the Krebs cycle; it is produced in the electron transport chain.

52. The conversion of pyruvate to acetyl CoA requires the presence of:
A) Oxygen
B) Carbon dioxide
C) Water
D) NADH
*Answer: A) Oxygen*
Explanation: Oxygen is required indirectly because acetyl CoA formation occurs within mitochondria where oxygen is present.

53. During the Krebs cycle, citrate is converted back into which molecule?
A) Oxaloacetate
B) Pyruvate
C) Acetyl CoA
D) Succinate
*Answer: A) Oxaloacetate*
Explanation: Citrate is eventually converted back into oxaloacetate to continue the cycle.

54. Which of the following is a product of the electron transport chain?
A) NAD+
B) FAD
C) ATP
D) Pyruvate
*Answer: C) ATP*
Explanation: The electron transport chain generates ATP from ADP and inorganic phosphate.

55. The movement of protons across the inner mitochondrial membrane drives the synthesis of:
A) Oxygen
B) Carbon dioxide
C) ATP
D) Glucose
*Answer: C) ATP*
Explanation: The movement of protons powers ATP synthase to produce ATP.

56. What is the purpose of the oxygen in the electron transport chain?
A) To accept electrons and form water
B) To release energy
C) To combine with glucose
D) To produce ATP
*Answer: A) To accept electrons and form water*
Explanation: Oxygen is the final electron acceptor, forming water.

57. Which of the following is NOT a step in the process of aerobic respiration?
A) Glycolysis
B) Fermentation
C) Krebs cycle
D) Electron transport chain
*Answer: B) Fermentation*
Explanation: Fermentation is an anaerobic process.

58. In which cellular compartment does the Krebs cycle occur?
A) Cytoplasm
B) Mitochondrial matrix
C) Chloroplasts
D) Endoplasmic reticulum
*Answer: B) Mitochondrial matrix*
Explanation: The Krebs cycle occurs in the mitochondrial matrix.

59. Which of the following is a characteristic of anaerobic respiration?
A) Produces more ATP than aerobic respiration
B) Produces carbon dioxide and water
C) Occurs in the absence of oxygen
D) Takes place in mitochondria
*Answer: C) Occurs in the absence of oxygen*
Explanation: Anaerobic respiration occurs in the absence of oxygen.

60. The primary purpose of the electron transport chain is to:
A) Generate ATP
B) Convert glucose to pyruvate
C) Produce carbon dioxide
D) Break down lipids
*Answer: A) Generate ATP*
Explanation: The electron transport chain generates ATP from the energy of electrons.

61. Which of the following is NOT a product of glycolysis?
A) ATP
B) Pyruvate
C) NADH
D) Carbon dioxide
*Answer: D) Carbon dioxide*
Explanation: Glycolysis does not produce carbon dioxide.

62. Which type of respiration occurs in the absence of oxygen?
A) Aerobic respiration
B) Anaerobic respiration
C) Photosynthesis
D) Transpiration
*Answer: B) Anaerobic respiration*
Explanation: Anaerobic respiration occurs without oxygen.

63. The final electron acceptor in the electron transport chain is:
A) NADH
B) FADH2
C) Oxygen
D) Carbon dioxide
*Answer: C) Oxygen*
Explanation: Oxygen is the final electron acceptor, forming water.

64. The breakdown of glucose during respiration releases energy in the form of:
A) Glucose
B) Oxygen
C) ATP
D) Carbon dioxide
*Answer: C) ATP*
Explanation: ATP is the primary form of energy released during respiration.

65. The enzyme responsible for catalyzing the breakdown of glucose during glycolysis is:
A) ATP synthase
B) Rubisco
C) Hexokinase
D) Pyruvate kinase
*Answer: C) Hexokinase*
Explanation: Hexokinase catalyzes the initial step of glycolysis.

66. How many carbon atoms are there in pyruvate?
A) 2
B) 3
C) 4
D) 6
*Answer: B) 3*
Explanation: Pyruvate has three carbon atoms.

67. Which of the following molecules is NOT generated during the Krebs cycle?
A) ATP
B) NADH
C) FADH2

D) CO2
*Answer: A) ATP*
Explanation: ATP is not directly generated in the Krebs cycle; it is produced in the electron transport chain.

68. The conversion of pyruvate to acetyl CoA requires the presence of:
A) Oxygen
B) Carbon dioxide
C) Water
D) NADH
*Answer: A) Oxygen*
Explanation: Oxygen is required indirectly because acetyl CoA formation occurs within mitochondria where oxygen is present.

69. During the Krebs cycle, citrate is converted back into which molecule?
A) Oxaloacetate
B) Pyruvate
C) Acetyl CoA
D) Succinate
*Answer: A) Oxaloacetate*
Explanation: Citrate is eventually converted back into oxaloacetate to continue the cycle.

70. Which of the following is a product of the electron transport chain?
A) NAD+
B) FAD
C) ATP
D) Pyruvate
*Answer: C) ATP*
Explanation: The electron transport chain generates ATP from ADP and inorganic phosphate.

71. The movement of protons across the inner mitochondrial membrane drives the synthesis of:
A) Oxygen
B) Carbon dioxide
C) ATP
D) Glucose
*Answer: C) ATP*
Explanation: The movement of protons powers ATP synthase to produce ATP.

72. What is the purpose of the oxygen in the electron transport chain?
A) To accept electrons and form water
B) To release energy
C) To combine with glucose
D) To produce ATP
*Answer: A) To accept electrons and form water*
Explanation: Oxygen is the final electron acceptor, forming water.

73. Which of the following is NOT a step in the process of aerobic respiration?
A) Glycolysis
B) Fermentation
C) Krebs cycle
D) Electron transport chain
*Answer: B) Fermentation*
Explanation: Fermentation is an anaerobic process.

74. In which cellular compartment does the Krebs cycle occur?
A) Cytoplasm
B) Mitochondrial matrix
C) Chloroplasts
D) Endoplasmic reticulum
*Answer: B) Mitochondrial matrix*
Explanation: The Krebs cycle occurs in the mitochondrial matrix.

75. Which of the following is a characteristic of anaerobic respiration?
A) Produces more ATP than aerobic respiration
B) Produces carbon dioxide and water
C) Occurs in the absence of oxygen
D) Takes place in mitochondria
*Answer: C) Occurs in the absence of oxygen*
Explanation: Anaerobic respiration occurs in the absence of oxygen.

76. The primary purpose of the electron transport chain is to:
A) Generate ATP
B) Convert glucose to pyruvate
C) Produce carbon dioxide
D) Break down lipids
*Answer: A) Generate ATP*
Explanation: The electron transport chain generates ATP from the energy of electrons.

77. Which of the following is NOT a product of glycolysis?
A) ATP
B) Pyruvate
C) NADH
D) Carbon dioxide
*Answer: D) Carbon dioxide*
Explanation: Glycolysis does not produce carbon dioxide.

78. Which type of respiration occurs in the absence of oxygen?
A) Aerobic respiration
B) Anaerobic respiration
C) Photosynthesis
D) Transpiration
*Answer: B) Anaerobic respiration*
Explanation: Anaerobic respiration occurs without oxygen.

79. The final electron acceptor in the electron transport chain is:
A) NADH
B) FADH2
C) Oxygen
D) Carbon dioxide
*Answer: C) Oxygen*
Explanation: Oxygen is the final electron acceptor, forming water.

80. The breakdown of glucose during respiration releases energy in the form of:
A) Glucose
B) Oxygen
C) ATP
D) Carbon dioxide
*Answer: C) ATP*
Explanation: ATP is the primary form of energy released during respiration.

81. The enzyme responsible for catalyzing the breakdown of glucose during glycolysis is:
A) ATP synthase
B) Rubisco
C) Hexokinase
D) Pyruvate kinase
*Answer: C) Hexokinase*
Explanation: Hexokinase catalyzes the initial step of glycolysis.

82. How many carbon atoms are there in pyruvate?
A) 2
B) 3
C) 4
D) 6
*Answer: B) 3*
Explanation: Pyruvate has three carbon atoms.

83. Which of the following molecules is NOT generated during the Krebs cycle?
A) ATP
B) NADH
C) FADH2
D) CO2
*Answer: A) ATP*
Explanation: ATP is not directly generated in the Krebs cycle; it is produced in the electron transport chain.

84. The conversion of pyruvate to acetyl CoA requires the presence of:
A) Oxygen
B) Carbon dioxide
C) Water
D) NADH
*Answer: A) Oxygen*
Explanation: Oxygen is required indirectly because acetyl CoA formation occurs within mitochondria where oxygen is present.

85. During the Krebs cycle, citrate is converted back into which molecule?
A) Oxaloacetate
B) Pyruvate
C) Acetyl CoA
D) Succinate
*Answer: A) Oxaloacetate*
Explanation: Citrate is eventually converted back into oxaloacetate to continue the cycle.

86. Which of the following is a product of the electron transport chain?
A) NAD+
B) FAD
C) ATP
D) Pyruvate
*Answer: C) ATP*
Explanation: The electron transport chain generates ATP from ADP and inorganic phosphate.

87. The movement of protons across the inner mitochondrial membrane drives the synthesis of:
A) Oxygen
B) Carbon dioxide
C) ATP
D) Glucose
*Answer: C) ATP*
Explanation: The movement of protons powers ATP synthase to produce ATP.

88. What is the purpose of the oxygen in the electron transport chain?
A) To accept electrons and form water
B) To release energy
C) To combine with glucose
D) To produce ATP
*Answer: A) To accept electrons and form water*
Explanation: Oxygen is the final electron acceptor, forming water.

89. Which of the following is NOT a step in the process of aerobic respiration?
A) Glycolysis
B) Fermentation
C) Krebs cycle
D) Electron transport chain

*Answer: B) Fermentation*
Explanation: Fermentation is an anaerobic process.

90. In which cellular compartment does the Krebs cycle occur?
A) Cytoplasm
B) Mitochondrial matrix
C) Chloroplasts
D) Endoplasmic reticulum
*Answer: B) Mitochondrial matrix*
Explanation: The Krebs cycle occurs in the mitochondrial matrix.

91. Which of the following is a characteristic of anaerobic respiration?
A) Produces more ATP than aerobic respiration
B) Produces carbon dioxide and water
C) Occurs in the absence of oxygen
D) Takes place in mitochondria
*Answer: C) Occurs in the absence of oxygen*
Explanation: Anaerobic respiration occurs in the absence of oxygen.

92. The primary purpose of the electron transport chain is to:
A) Generate ATP
B) Convert glucose to pyruvate
C) Produce carbon dioxide
D) Break down lipids
*Answer: A) Generate ATP*
Explanation: The electron transport chain generates ATP from the energy of electrons.

93. Which of the following is NOT a product of glycolysis?
A) ATP
B) Pyruvate
C) NADH
D) Carbon dioxide
*Answer: D) Carbon dioxide*
Explanation: Glycolysis does not produce carbon dioxide.

94. Which type of respiration occurs in the absence of oxygen?
A) Aerobic respiration
B) Anaerobic respiration
C) Photosynthesis
D) Transpiration
*Answer: B) Anaerobic respiration*
Explanation: Anaerobic respiration occurs without oxygen.

95. The final electron acceptor in the electron transport chain is:
A) NADH
B) FADH2
C) Oxygen
D) Carbon dioxide
*Answer: C) Oxygen*
Explanation: Oxygen is the final electron acceptor, forming water.

96. The breakdown of glucose during respiration releases energy in the form of:
A) Glucose
B) Oxygen
C) ATP
D) Carbon dioxide
*Answer: C) ATP*
Explanation: ATP is the primary form of energy released during respiration.

97. The enzyme responsible for catalyzing the breakdown of glucose during glycolysis is:
A) ATP synthase
B) Rubisco
C) Hexokinase
D) Pyruvate kinase
*Answer: C) Hexokinase*
Explanation: Hexokinase catalyzes the initial step of glycolysis.

98. How many carbon atoms are there in pyruvate?
A) 2
B) 3
C) 4
D) 6
*Answer: B) 3*
Explanation: Pyruvate has three carbon atoms.

99. Which of the following molecules is NOT generated during the Krebs cycle?
A) ATP
B) NADH
C) FADH2
D) CO2
*Answer: A) ATP*
Explanation: ATP is not directly generated in the Krebs cycle; it is produced in the electron transport chain.

100. The conversion of pyruvate to acetyl CoA requires the presence of:
A) Oxygen
B) Carbon dioxide
C) Water
D) NADH
*Answer: A) Oxygen*
Explanation: Oxygen is required indirectly because acetyl CoA formation occurs within mitochondria where oxygen is present.

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