More is the leaf area,..................................is the rate of transpiration.

Explanation

**Step-by-Step Solution:**

1. **Understanding Transpiration**: Transpiration is the process through which plants lose water in the form of vapor. This process primarily occurs through small openings on the leaves called stomata.

2. **Role of Leaf Area**: The leaf area of a plant is crucial because it determines the surface area available for transpiration. A larger leaf area means more stomata can be present, which increases the potential for water vapor to escape.

3. **Stomata and Guard Cells**: Stomata are the pores on the leaf surface that facilitate gas exchange and transpiration. The guard cells surrounding the stomata control their opening and closing, which regulates the rate of transpiration.

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