Smaller plants lose more water per unit area of leaf as compared to the larger plants due to

Options

A. high root Shoot ratio in former
B. low Root Shoot ratio in former
C. more stomatal frequency
D. value of stomatal index is high .

Answer

### Step-by-Step Solution:

1. **Understanding Water Loss in Plants**:
Smaller plants typically have a higher rate of water loss per unit area of leaf compared to larger plants. This phenomenon can be attributed to various physiological and structural factors.

2. **Root-Shoot Ratio**:
The root-shoot ratio refers to the proportion of root biomass to shoot biomass in a plant. A higher root-shoot ratio indicates that a plant has more roots relative to its shoots, which can enhance nutrient and water absorption.

3. **Impact of Root-Shoot Ratio on Water Loss**:
Smaller plants often have a higher root-shoot ratio. This means they have more roots relative to their shoots, which allows them to absorb more water. However, smaller plants also tend to have a higher surface area to volume ratio, leading to increased transpiration rates.

4. **Analyzing the Options**:
- **Option 1: High root-shoot ratio** - This is correct because a higher root-shoot ratio in smaller plants allows for more efficient water uptake, but the high surface area leads to more water loss.
- **Option 2: Low root-shoot ratio** - This is incorrect as it does not explain the increased water loss in smaller plants.
- **Option 3: More stomatal frequency** - This option is incorrect as it does not directly relate to the size of the plant but rather to the number of stomata present.
- **Option 4: High stomatal index** - This is also incorrect as it does not explain the water loss in relation to plant size.

5. **Conclusion**:
The correct answer is **Option 1: High root-shoot ratio**. Smaller plants lose more water per unit area of leaf due to their higher root-shoot ratio, which allows for more efficient water absorption but also leads to increased transpiration.