1. Leaves

2. Structure of a leaf Petiole – joins leaf to the stem
Midrib and veins – Help in transporting water and food.
Sessile – If there is no petiole.

3. Reticulate : net- like pattern Parallel: veins lie side by side
Venation
Reticulate : net- like pattern
Parallel: veins lie side by side

4. Simple & Compound Leaves
Base of the stalk of the simple leaf is swollen
Base of main stalk, (not leaflet) is swollen
Leaf is broken into leaflets

5. Phyllotaxy – arrangement of the leaves

6. Functions
1. Photosynthesis – Leaves prepare starch as food. They use energy from sunlight, carbon dioxide from air and water from soil.

7. 2. Transpiration – leaves give off the excess water through the stomata. Stomata are the small openings on the lower surface of leaves.
This helps to draw water through the roots.

8. Leaf Modifications
ii. Prevention of water loss – Leaves are reduced to spines or tiny scale leaves, which drop off
i. Food Storage – onion bulb underground leaves are fleshy

9. …Leaf modifications…
iii. PROTECTION- Leaves protect the bud from winter cold
iv. ADDITIONAL SUPPORT – Leaf tendrils

10. v. Insectivorous plants – Leaves are modified to trap insects – venus flytrap, pitcher plant and sundew