Stomata

• what are stomata?

  they are small pores on the above-ground parts of plants and occur mostly on the lower surfaces of leaves
• what is each pore on leaves bounded by?

  by 2 guard cells
• why are guard cells unusual?

  because they are the only epidermal cells with chloroplasts and they have unevenly thickened walls, with the inner wall, next to the pore in many species, being thicker than the outer wall
• what part of the stoma can change?

  the width of it
• what does it mean that the width of the stoma can change?

  it means that the stoma control the exchange of gases between the atmosphere and the internal tissues of the leaf
• what is this an image of?

  its the surface view of a leaf lower epidermis