- Study guides, Class notes & Summaries

Lesson 8-Leaf Structure & Transpiration what you need to know latest exam update epidermis - the outermost layer of the leaf. guard cell - pairs of cells that surround stomata and control their opening and closing. stoma - is the pore, which is surrounded by two guard cells. stomata - the collection of stoma found inside the lower epidermis of plant leaves. osmosis - the diffusion of water. solute - a substance that is dissolved in a solution. stomatal unit - a pair of gua...