Which of the following is correct regarding respiration ?

Options

A. No organism can live without respiration.
B. It takes place at every time day and night.
C. It involves production of carbon dioxide and water.
D. All of these

Answer

### Step-by-Step Solution:

1. **Understanding Respiration**: Respiration is a biochemical process that occurs in living organisms to produce energy. It involves the breakdown of glucose in the presence of oxygen.

2. **Analyzing the Statements**:
- **Statement 1**: "No organism can live without respiration."
- This is true because respiration is essential for energy production, which is necessary for all life processes.
- **Statement 2**: "It takes place at every time day and night."
- This is also true as respiration is a continuous process that occurs in organisms regardless of the time of day.
- **Statement 3**: "It involves production of carbon dioxide and water."
- This statement is correct because during the process of respiration, glucose is broken down into carbon dioxide and water, along with the release of energy.
- **Statement 4**: "All of these."
- Since all the previous statements are true, this statement is also correct.

3. **Conclusion**: Since all the statements regarding respiration are correct, the answer to the question is "All of these."

### Final Answer: All of these.

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