structure of the leaf:
the upper epidermis is transparent so that sunlight can be absorbed
the cells in the palaside layer is at the top to take in maximm sunlight, they are also filled with choroplast which absorb the light energy for PHOTSYNTHSIS
the spongy layer (mestophyll) is connected to the stomarta for maximum exchange of gas.
lower epidermis contains most of the stomata.
stomata allows diffustion of gases such as carbondioxide and oxygen in an out of the leaf
guard cells are there to stop water loss
veins contain xylem and phloem to transport water and sugar through the leaf.