Rate of transpiration in inversely related to

Options

A. Humidity
B. Light
C. Temperature
D. Water

Answer

To solve the question regarding the relationship between the rate of transpiration and various environmental factors, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Transpiration**:
- Transpiration is the process by which water vapor is lost from the plant to the atmosphere, primarily through small openings called stomata.

2. **Factors Affecting Transpiration**:
- Several environmental factors influence the rate of transpiration, including humidity, light, temperature, and water availability.

3. **Analyzing Humidity**:
- Humidity refers to the amount of water vapor present in the air. When humidity is high, the concentration gradient between the inside of the leaf (where water vapor is) and the outside air (where water vapor is less) decreases.

4. **Inversely Related**:
- When humidity is high, the rate of transpiration decreases because the water vapor inside the leaf does not diffuse out as easily. This indicates an inverse relationship: as humidity increases, the rate of transpiration decreases.

5. **Comparing Other Factors**:
- **Light**: Increased light intensity generally increases the rate of transpiration because it stimulates stomatal opening.
- **Temperature**: Higher temperatures increase the rate of transpiration due to increased evaporation of water.
- **Water Availability**: More water available in the soil leads to increased transpiration as the plant can absorb more water.

6. **Conclusion**:
- Among the options given (humidity, light, temperature, water), the only factor that is inversely related to the rate of transpiration is humidity. Thus, the correct answer is **option a: Humidity**.

### Final Answer:
The rate of transpiration is inversely related to **humidity**.

---