Question

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

• A. Lenticels
• B. Guard cells
• C. Bundle sheath cells
• D. Bulliform cells

Answer 1

The correct option is D Bulliform cells

Bulliform cells are large, empty, colourless cells found in the adaxial epidermis of grasses. These cells absorb water and become turgid due to which the leaf surface is exposed. However, during dry weather, these cells become flaccid due to water loss. This causes the leaves to curl inward to minimise loss of water.

Lenticels are lens-shaped apertures found in the bark of trees. They facilitate the exchange of gases between the outer atmosphere and internal tissues of the stem.

The vascular bundles of both dicot and monocot leaf are surrounded by bundle sheath cells. The bundle sheath cells are compactly arranged cells and regulate the movement of substances between the vascular tissues and other parts of leaves.

The guard cells are specialized cells present in epidermis of leaves. The two guard cells enclose a pore in between them, known as stomatal pore. This pore helps in the exchange of gases. The guard cells are bean or dumbbell shaped.