Question

The cells are chlorophyllous, fewer in number, unique in shape and inner walls thick. The description fits into

• A. Guard cells
• B. Subsidiary cells
• C. Passage cells
• D. Bulliform cells

Answer 1

The correct option is A Guard cells

Each stomatal pore is surrounded by two guard cells that assist in stomatal opening driven by turgidity of guard cells. The only epidermal cells with unevenly thickened walls and chloroplasts are the guard cells.

The epidermal cells that border the guard cells are called subsidiary cells, which lack chloroplast.

Passage cells are thin walled, achlorophyllous cells present opposite to protoxylem in endodermis and serve to transport absorbed sap from root hair to xylem.

The large, bubble-shaped epidermal cells that are present in groups on the upper surface of the leaves in monocots bulliform cells; they do not have chloroplast and regulate the turgor pressure driven rolling and unrolling of leaves.