In a certain experiment, a potted plant was kept in an inverted bell jar such that no external air passed into the bell jar. After a span of two weeks, the air in the bell jar was tested on various parameters
It can be concluded from the above experiment that the air in the bell jar had

Options

A. low concentration of oxygen
B. high concentration of oxygen
C. low concentration of water vapor
D. high concentration of carbon dioxide

Answer

### Step-by-Step Solution:

1. **Understanding the Experiment**: The experiment involves placing a potted plant in an inverted bell jar, creating a closed environment where no external air can enter or exit.

2. **Duration of the Experiment**: The plant is kept in this closed environment for two weeks, allowing time for physiological processes to occur.

3. **Key Processes Involved**:
- **Photosynthesis**: This is the process by which plants use carbon dioxide (CO2) and release oxygen (O2) in the presence of sunlight.
- **Respiration**: This is the process where plants (and animals) take in oxygen (O2) and release carbon dioxide (CO2).

4. **Analyzing Gas Exchange**:
- In the closed environment, the plant will perform both photosynthesis and respiration.
- During the day, photosynthesis will dominate, leading to a net increase in oxygen levels as CO2 is consumed and O2 is released.
- At night, respiration occurs, where the plant consumes some of the oxygen and releases CO2, but this is minimal compared to the amount produced during the day.

5. **Conclusion After Two Weeks**:
- Since the plant has been in a closed environment for two weeks, the overall effect of photosynthesis will lead to a higher concentration of oxygen in the air inside the bell jar.
- Conversely, the concentration of carbon dioxide will decrease due to its consumption during photosynthesis.

6. **Final Assessment**: After testing the air in the bell jar, it can be concluded that the air has a **high concentration of oxygen (O2)** and a **low concentration of carbon dioxide (CO2)**.

### Final Answer:
The air in the bell jar had a **high concentration of O2**.

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