Cross Section of a Leaf Number Name Function The underside of the leaf is covered in these pores that open and close to allow gases in and out of the leaf A waterproof Layer that stops water loss out of the leaf Layer with cells that are packed with chloroplasts and are long to maximise photosynthesis. Layer of cells with no chloroplast that allow light to pass through Spacious area for gas exchange processes to occur within the leaf Two cells that control the opening and closing of a leaf stoma Vascular tissue used to transport water and minerals up from the roots to the rest of the plants