With reference to cellular respiration, consider the following statements: 1. It is the process of synthesis of food within the cell using energy. 2. It takes place in the cells of all living organisms. 3. The breakdown of food always occurs in the absence of oxygen. Which of the statements given above is/are correct?

Correct Option The correct option is (b) 2 only. Explanation Cellular respiration is a vital biochemical process occurring in the cells of organisms. It involves the enzymatic breakdown of glucose to release energy, which is trapped in the form of ATP (Adenosine Triphosphate) for use in various cellular activities. Statement-wise Analysis - Statement 1 is Incorrect. Cellular respiration is a catabolic process involving the breakdown of food sources (like glucose) to release energy. The process of synthesizing food using energy is called photosynthesis (an anabolic process), which occurs in plants and certain bacteria. - Statement 2 is Correct. Cellular respiration takes place in the cells of all living organisms, including plants, animals, and microorganisms. It is essential for maintaining life as it provides the energy required for all metabolic activities. - Statement 3 is Incorrect. The breakdown of food does not always occur in the absence of oxygen. Respiration is classified based on oxygen requirement: - Aerobic Respiration: Occurs in the presence of oxygen, leading to the complete breakdown of glucose into carbon dioxide and water. - Anaerobic Respiration: Occurs in the absence of oxygen, leading to partial breakdown (e.g., fermentation in yeast or lactic acid formation in muscles). Key Takeaway Cellular respiration is the energy-releasing breakdown of glucose that occurs in all living cells. It is distinct from photosynthesis (food synthesis) and can occur either aerobically (with oxygen) or anaerobically (without oxygen).

NCERT Class 7 Science — Chapter 2: Respiration in organisms

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With reference to cellular respiration, consider the following statements:

It is the process of synthesis of food within the cell using energy.
It takes place in the cells of all living organisms.
The breakdown of food always occurs in the absence of oxygen.

Which of the statements given above is/are correct?

Official previous-year question

Verified 1 Aug 2026.

Options

A1 only
B2 only
C1 and 3 only
D1, 2 and 3

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Solution

Correct Option

The correct option is (b) 2 only.

Explanation

Cellular respiration is a vital biochemical process occurring in the cells of organisms. It involves the enzymatic breakdown of glucose to release energy, which is trapped in the form of ATP (Adenosine Triphosphate) for use in various cellular activities.

Statement-wise Analysis

Statement 1 is Incorrect. Cellular respiration is a catabolic process involving the breakdown of food sources (like glucose) to release energy. The process of synthesizing food using energy is called photosynthesis (an anabolic process), which occurs in plants and certain bacteria.
Statement 2 is Correct. Cellular respiration takes place in the cells of all living organisms, including plants, animals, and microorganisms. It is essential for maintaining life as it provides the energy required for all metabolic activities.
Statement 3 is Incorrect. The breakdown of food does not always occur in the absence of oxygen. Respiration is classified based on oxygen requirement:
- Aerobic Respiration: Occurs in the presence of oxygen, leading to the complete breakdown of glucose into carbon dioxide and water.
- Anaerobic Respiration: Occurs in the absence of oxygen, leading to partial breakdown (e.g., fermentation in yeast or lactic acid formation in muscles).

Key Takeaway

Cellular respiration is the energy-releasing breakdown of glucose that occurs in all living cells. It is distinct from photosynthesis (food synthesis) and can occur either aerobically (with oxygen) or anaerobically (without oxygen).

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Correct Option

The correct option is (b) 2 only.

Explanation

Statement-wise Analysis

Statement 1 is Incorrect. Cellular respiration is a catabolic process involving the breakdown of food sources (like glucose) to release energy. The process of synthesizing food using energy is called photosynthesis (an anabolic process), which occurs in plants and certain bacteria.
Statement 2 is Correct. Cellular respiration takes place in the cells of all living organisms, including plants, animals, and microorganisms. It is essential for maintaining life as it provides the energy required for all metabolic activities.
Statement 3 is Incorrect. The breakdown of food does not always occur in the absence of oxygen. Respiration is classified based on oxygen requirement:
- Aerobic Respiration: Occurs in the presence of oxygen, leading to the complete breakdown of glucose into carbon dioxide and water.
- Anaerobic Respiration: Occurs in the absence of oxygen, leading to partial breakdown (e.g., fermentation in yeast or lactic acid formation in muscles).