The stomatal pore is guarded by two kidney shaped guard cells. Name the epidermal cells surrounding the guard cells. How does a guard cell differ from an epidermal cell ?

The epidermal cells surrounding the guard cells are called subsidiary cells or accessory cells.

Difference between Guard Cells and Epidermal Cells:

1. Shape:
   • Guard cells are kidney-shaped (in dicots) or dumbbell-shaped (in monocots).
   • Epidermal cells are usually irregular or rectangular in shape.
2. Function:
   • Guard cells regulate the opening and closing of stomatal pores, thus controlling transpiration and gas exchange.
   • Epidermal cells mainly provide protection and cover the leaf surface.
3. Chloroplasts:
   • Guard cells contain chloroplasts and can perform photosynthesis.
   • Epidermal cells lack chloroplasts (except subsidiary cells in some cases).
4. Thickness of Cell Wall:
   • In guard cells, the inner wall is thicker and the outer wall is thinner to facilitate stomatal movement.
   • Epidermal cells have uniformly thickened walls.