Leaf structure

• Cuticle: waxy layer that prevents water loss from top of the leaf

  
• Epidermis: transparent cell that allows sunlight to pass through to the palisade cell

  
• Palisade: found at the top of the cell and contains many chloroplasts which absorbs sunlight.

  
• Spongy mesophyll layer: irregularly shaped cells which create air spaces to allow gaseous exchange to take place; do not contain many chloroplasts

  
• Vascular Bundle: made up of xylem and phloem

  
• Xylem: vessel which transports water and dissolved minerals and has lignified walls made of cellulose

  
• Phloem: vessel which transports nutrients

  
• Stomata: little holes that opens and closes to allow gaseous exchange to take place. The stomata close to prevent water loss and open to let gases come in and out. When guard cells lose water, the stoma close (at night), while the stoma open when guard cells gain water & swell (during the day).