Which is not a factor affecting transpiration

Options

A. efficiency of water uptake by roots
B. leaf area
C. leaf structure
D. efficiency of mineral uptake by roots

Answer

**Step-by-Step Solution:**

1. **Understanding Transpiration**:
- Transpiration is the process by which water vapor is lost from the aerial parts of the plant, primarily through stomata. It can also occur through cuticles and lenticels.

2. **Identifying Factors Affecting Transpiration**:
- There are various factors that can influence the rate of transpiration, which can be categorized into environmental factors (like humidity, sunlight, and temperature) and internal factors (like leaf area and leaf structure).

3. **Analyzing the Options**:
- **Option 1: Efficiency of water uptake by roots**: This affects transpiration because if roots absorb more water, more water can be lost through transpiration.
- **Option 2: Leaf area**: A larger leaf area allows for more stomata, which can increase the rate of transpiration.
- **Option 3: Leaf structure**: The structure of the leaf, including the number and distribution of stomata, also affects transpiration rates.
- **Option 4: Efficiency of mineral uptake by roots**: While minerals are absorbed by roots, they do not directly influence the rate of transpiration. Transpiration primarily involves the movement of water, not minerals.

4. **Conclusion**:
- The option that is **not a factor affecting transpiration** is **Efficiency of mineral uptake by roots**. This is because transpiration is primarily concerned with water loss, and while minerals are transported with water, their uptake does not influence the transpiration rate.

**Final Answer**: Efficiency of mineral uptake by roots.

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