1. Internal Structure of the Leaf

3. a) Cuticle: Waxy layer water proofing upper leaves.
b) Upper epidermis: Upper layer of cells. No chloroplasts. Protection.

4. c) Palisade Mesophyll: Tightly packed upper layer of chloroplast containing cells.
d) Spongy Mesophyll: Lower layer of chloroplast containing cells. Air spaces around them. \
e) Lower Epidermis: Lower external layer of cells in leaf.

5. f) Vascular Bundle: Bundle of many vessels (xylem and phloem) for transport.
g) Xylem: Living vascular system carrying water & minerals throughout plant.
h) Phloem: Living vascular system carrying dissolved sugars and organic compounds throughout plant.

6. i) Guard Cells: 2 cells surrounding stomata that control rate of gas & water exchange.
j) Stomata: Opening between guard cells for gas & water exchange. (See Diagram below.)

7. i) Guard Cells: 2 cells surrounding stomata that control rate of gas & water exchange.
j) Stomata: Opening between guard cells for gas & water exchange. (See Diagram below.)