Question

Guard cells help in

• A. Protection against grazing
• B. Transpiration
• C. Guttation
• D. Fighting against infection

Answer 1

The correct option is B Transpiration

Each stoma is surrounded by two specialized epidermal cells, called guard cells. They differ from epidermal cells in their shape (kidney or bean-shaped) and in the presence of chloroplasts. The immediate cause of the opening or closing of the stomata is a change in the turbidity of the guard cells. Guard cells help in transpiration. When the osmotic concentration of guard cells increases, water comes in and guard cells become turgid and stomata get open. Whenever osmotic concentration of guard cells decreases water moves out, guard cells become flaccid and hence get closed.