Grass leaves curl inwards during very dry weather. Select the most appropriate reason from the following:

🔑 Key Points
→ Concept: The monocot leaf is called the isobilateral leaf.
→ It is oriented parallel to the main axis of the plant and also parallel to the direction of sunlight.

📌 Important Points
→ None

📝 Additional Information
→ Explanation:

The stomata are present on both surfaces of the epidermis.
The mesophyll is not differentiated into palisade and spongy parenchyma.
In grasses, the adaxial epidermal cells present along the leaf vein get modified into large, empty, and colorless cells called bulliform cells.
When bulliform cells have absorbed water and are turgid, the leaf surface is exposed.
When bulliform cells undergo water stress (especially during dry weather conditions), they become flaccid (lack turgidity and are not swollen). In this condition, the leaf surface curls inwards to avoid loss of water.