Mesophyll(a) (top) The central mesophyll is sandwiched between an upper and lower epidermis. The mesophyll has two layers: an upper palisade layer and a lower spongy layer. Stomata on the leaf underside allow gas exchange. A waxy cuticle covers all aerial surfaces of land plants to minimize water loss.
Beside this, what is the main function of the epidermal tissue?
Function. Serving as a plant's skin, epidermis cells protect internal tissues from the outside world by creating a barrier. But the epidermis also serves a variety of other functions for plants. When stomata open to exchange gases during photosynthesis, water is also lost through these small openings by evaporation.
Why do you think stomata are only in the lower epidermis?
Explanation: All surfaces of the leaf have some amount of stomata for regulating gas exchange for photosynthesis. However, the lower epidermis (the underside of the leaf) has more, because it is more often in the shade and so it is cooler, which means evaporation won't take place as much.
What is the upper and lower epidermis of a plant?
The cuticle and upper epidermis provide protection for the plant. Below that is the palisade layer, which is the location of photosynthesis within the leaf. Below the palisade layer is the spongy layer, which contains cells that are more spread out, allowing for air pockets.