When does the process of respiration take place in plants?

Options

A. Only when there is no photosynthesis.
B. Only when stomata are open.
C. Only when there is a high oxygen concentration.
D. Throughout day and night.

Answer

### Step-by-Step Text Solution:

1. **Understanding Respiration in Plants**:
- Respiration is a vital process that occurs in all living organisms, including plants. It involves a series of chemical reactions that convert glucose and oxygen into energy, carbon dioxide, and water.

2. **When Does Respiration Occur?**:
- Respiration in plants occurs continuously, both during the day and at night. This is because plants require energy for various functions, and respiration is the process through which they obtain this energy.

3. **Role of Photosynthesis**:
- While photosynthesis (the process by which plants convert light energy into chemical energy) occurs during the day when there is sunlight, respiration does not stop when photosynthesis is happening. Instead, both processes can occur simultaneously.

4. **Gas Exchange Mechanism**:
- Plants exchange gases through small openings called stomata, which are primarily located on the leaves. During respiration, plants take in oxygen and release carbon dioxide.

5. **Conclusion**:
- Therefore, the correct answer to the question "When does the process of respiration take place in plants?" is that respiration occurs throughout the day and night.