Monocot Leaf

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

1. Tyloses in vessels

2. Closure of stomata

3. Flaccidity of bulliform cells

4. Shrinkage of air spaces in spongy mesophyll

Large, empty colourless cells of the adaxial epidermis along the veins of grass leaves are:

1.	Lenticels	2.	Guard cells
3.	Bundle sheath cells	4.	Bulliform cells

Bulliform cells are responsible for

1.	Protecting the plant from salt stress.
2.	Increased photosynthesis in monocots.
3.	Providing large spaces for storage of sugars.
4.	Inward curling of leaves in monocots.