1. Leaves
structure and function
By Bhuvan

2. Leaves
Ask students to collect leaves and bring them to the class. Show them different leaves including simple and compound leaves. Let them touch and feel the texture. The teacher could also discuss venation.

3. Function of leaves Trap light energy for photosynthesis
Producing sugar from photosynthesis
Exchange of gases – oxygen and carbon dioxide

5. Structure Helps to catch more light energy
Wide
Helps to catch more light energy
Thin
Help get carbon dioxide from bottom to top of leaf for photosynthesis

6. Leaf structure Greener on top CO2 gets in here
Teachers can supplement this by showing the students the onion peel under a microscope.
CO2 gets in here

7. Leaf diagram – palisade layer
Most chlorophyll
Have a discussion with the students on the density of chlorophyll leading to photosynthesis.
CO2

8. Leaf cell - palisade Position? Upper surface of leaf Features?
Box shape
Chloroplasts
Function?
Photosynthesis

9. Stoma is a small hole Its size is controlled by 2 guard cells closed
open

10. Gas exchange
Leaves are designed to allow carbon dioxide to get to the main chlorophyll layer at the top of the leaf
They have small holes called stomata on the under surface
Each hole is open & closed by 2 guard cells

11. Leaf diagram – stoma and guard cells

12. Stoma position

13. Stoma function is for gas exchange in the leaf
oxygen
Guard cell
Provided plant is photosynthesising
Carbon dioxide

14. Stomata open and close at different times of the day
When it is light the plant needs CO2 for photosynthesis so the stoma open
At night (darkness) they close

15. Gas exchange

16. T S of stem

17. The End