What is the common value of PQ (Photosynthetic quotient) of a leaf ?

Options

A. gt1
B. lt1
C. 1
D. 0

Explanation

To determine the common value of the Photosynthetic Quotient (PQ) for a leaf, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Photosynthetic Quotient (PQ)**:
- The Photosynthetic Quotient (PQ) is defined as the ratio of the rate of oxygen evolution to the rate of carbon dioxide uptake during photosynthesis.

2. **Identifying the Components**:
- In the process of photosynthesis, carbon dioxide (CO2) is taken up by the plant, and oxygen (O2) is released as a byproduct.

3. **Establishing the Ratio**:
- The formula for PQ can be expressed as:
\[ PQ = \frac{\text{Rate of Oxygen Evolution}}{\text{Rate of Carbon Dioxide Uptake}} \]

4. **Analyzing the Common Value**:
- For most higher plants, the common value of PQ is approximately 1. This indicates that the amount of oxygen produced is roughly equal to the amount of carbon dioxide consumed.

5. **Considering Other Factors**:
- It is important to note that the PQ value can vary slightly based on conditions such as light intensity, temperature, and the presence of other metabolic processes like respiration and photorespiration. However, the standard or common value for a leaf remains around 1.

6. **Conclusion**:
- Therefore, the common value of the Photosynthetic Quotient (PQ) for a leaf is 1.

### Final Answer:
The common value of the Photosynthetic Quotient (PQ) for a leaf is **1**.

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