Why does the lower epidermis have more stomata than the upper epidermis of a leaf?
Plant undergoes a process called transpiration. Transpiration is the removal of water (vapour) from the upper parts of the plant (stem, leaves). The opening and closing of stomata have huge influence on the rate of transpiration. If the amount of stomata per unit area is more in the upper surface of the leaf then, more transpiration occurs which might be detrimental for the plant. Since, the upper leaf blade is directly faced to the sun, the rate of transpiration increases. Hence, to prevent excessive transpiration, stomata are more in lower surface i.e. relatively less transpiration happens from the lower epidermis. Plants also remove water in the form of (liquid), this is guttation. Stomata has no influence on this process. Note: 1. Transpiration involves water vapour while guttation happens in the form of liquid (not water vapour). 2. Transpiration is a necessary evil i.e. needed for plant, but excessive is harmful. 3. Closing and opening of stomatal pore is due to two surrounding g
