Leaves have a structure and perform functions that allow them to effectively capture light for photosynthesis and exchange gases. Leaves are typically wider at the top to catch more light, and thinner toward the bottom to allow for efficient gas exchange. They contain structures like the palisade layer and stomata that facilitate photosynthesis and the transport of carbon dioxide into the leaf and oxygen out. Stomata, which are small openings with guard cells, are primarily located on the underside of leaves and can open and close to regulate gas exchange as needed throughout the day for photosynthesis.

1. LeavesLeaves
By Bhuvan
structure and function

2. LeavesLeaves

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

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

6. Leaf structureLeaf structure
Greener on top
CO2 gets in
here

7. Leaf diagram – palisadeLeaf diagram – palisade
layerlayer
CO2
Most
chlorophyll

8. Leaf cell -Leaf cell -
palisadepalisade
Position?Position?
Upper surface ofUpper surface of
leafleaf
Features?Features?
Box shapeBox shape
ChloroplastsChloroplasts
Function?Function?
PhotosynthesisPhotosynthesis

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

10. Gas exchangeGas exchange
 Leaves are designed to allow carbonLeaves are designed to allow carbon
dioxide to get to the main chlorophylldioxide to get to the main chlorophyll
layer at the top of the leaflayer at the top of the leaf
 They have small holes called stomata onThey have small holes called stomata on
the under surfacethe under surface
 Each hole is open & closed by 2 guardEach hole is open & closed by 2 guard
cellscells

11. Leaf diagram –Leaf diagram –
stoma and guard cellsstoma and guard cells

12. Stoma positionStoma position

13. Stoma function is forStoma function is for
gas exchange in thegas exchange in the
leafleaf
Carbon
dioxide
oxygenGuard
cell
Provided plant is
photosynthesising

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 exchangeGas exchange

16. T S of stemT S of stem

17. The End