Cellular respiration is

Options

A. Continuous
B. Intermittent
C. Performed at intervals
D. Held when energy is required

Answer

**Step-by-Step Solution:**

1. **Understanding Cellular Respiration:**
- Cellular respiration is defined as the process of oxidizing food to produce energy. This process is essential for the survival of cells and organisms.

2. **Purpose of Cellular Respiration:**
- The primary aim of cellular respiration is to generate energy. This energy is crucial for various biological processes that sustain life.

3. **Energy Utilization:**
- The energy produced through cellular respiration is utilized in several vital processes such as:
- Digestion: Breaking down food for nutrients.
- Circulation: Moving blood and nutrients throughout the body.
- Excretion: Removing waste products from the body.
- These processes occur regularly and continuously throughout the day.

4. **Nature of Cellular Respiration:**
- Given that the energy is required for these processes on a continuous basis, cellular respiration must also occur continuously.
- Therefore, it can be concluded that cellular respiration is a continuous process.

5. **Evaluating the Options:**
- Option A: Continuous - This is the correct answer as it aligns with the understanding that energy is needed continuously.
- Option B: Intermittent - This is incorrect as it suggests that respiration occurs at intervals, which is not the case.
- Option C: Performed at intervals - This is also incorrect for the same reason as option B.
- Option D: Held when energy is required - This is misleading since energy is required continuously, not just at specific times.

6. **Final Conclusion:**
- The correct answer is option A: Continuous.