When the guard cells are turgid, the stomata ___________.

Explanation

**Step-by-Step Solution:**

1. **Understanding Guard Cells**: Guard cells are specialized cells that surround the stomatal pore on the surface of leaves. They play a crucial role in regulating gas exchange and transpiration in plants.

2. **Turgidity of Guard Cells**: Turgidity refers to the state of being swollen or firm due to the uptake of water. When guard cells absorb water from their surroundings, they become turgid.

3. **Shape Change**: When guard cells become turgid, they change shape. They swell and curve away from each other, which causes the stomatal pore to open.

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