Question

Bulliform or motor cells are present on
A. Root
B. Stem
C. Isobilateral leaf
D. Dorsiventral leaf

Answer 1

In groups of many monocots, bulliform or motor cells are large, bubble-shaped epidermal cells that occur on the upper surface of the leaves.

Complete Answer:
- Bulliform cells are the cells that are distributed between the epidermal cells of the leaf. They are important for the storage of water. Bulliform cells help to roll leaves under stress conditions to prevent water loss by transpiration. Therefore, the transpiration mechanism is regulated by them. Under favourable conditions as well, they unroll the leaves. Bulliform cells are predominantly discovered in grass.
- Generally, they are present near the leaf 's mid-vein portion and are wide, empty and colourless. They are suspected, but not proven, to be involved in leaf tissue folding and unfolding in order to regulate the strength of light and minimise overall water loss.

The working process of bulliform cells is:
- The bulliform cells absorb water when the water source is adequate for the plant and they become turgid due to the absorption of water. The leaf straightens up when they are turgid and it is exposed. The straightening of the leaf enables the loss of water. Whereas, on the other hand, these cells lose water at the moment of inadequate water supply and become flaccid due to water loss.
- During the water tension, when they are flaccid, the leaf is curled inwards so that the leaf is less exposed. The curling minimises the loss of water. Therefore, under unfavourable or stress situations, the bulliform cells mitigate water loss.
- These water containing colourless epidermal cells present on the isobilateral leaf or monocot leaf's adaxial epidermis are called bulliform cells.

The correct Answer is option (C) Isobilateral leaf.

Note: They are found in grass and grass like flowering plants with one layer of cells with or without chloroplasts. They permit most of the light that strikes as they are very transparent.