Plants Structure – Leaves stem stem roots roots. Leaves

PlantsPlants

StructureStructure – –

LeavesLeaves

stem stem

rootsroots

LeavesLeaves

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

StructureStructureWide

Helps to catch more light energy

Thin

Help get carbon dioxide from bottom to top of leaf for photosynthesis

Leaf structureLeaf structure

Greener on top

CO2 gets in here

Leaf diagram – palisade layerLeaf diagram – palisade layer

CO2

Most chlorophyll

Leaf cell - Leaf cell - palisadepalisade

Position?Position?

Upper surface of Upper surface of leafleaf

Features?Features?

Box shapeBox shape

ChloroplastsChloroplasts

Function?Function?PhotosynthesisPhotosynthesis

Gas exchange Gas exchange

Leaves are designed to allow carbon Leaves are designed to allow carbon dioxide to get to the main chlorophyll dioxide 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 on They have small holes called stomata on the under surfacethe under surface

Each hole is open & closed by 2 guard Each hole is open & closed by 2 guard cells cells

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

Stoma positionStoma position

Stoma is a small holeStoma is a small holeIts size is controlled by 2 guard cells

closed open

Stoma function is for gas Stoma function is for gas exchange in the leafexchange in the leaf

Carbon dioxide

oxygenGuard cell

Provided plant is photosynthesising

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

Gas exchangeGas exchange

Roots – function and Roots – function and structurestructure

Hold plant in positionHold plant in position Absorb water and minerals Absorb water and minerals

from the soilfrom the soil Specialised cells to increase Specialised cells to increase

surface area for water intakesurface area for water intake

Wheat Wheat seedseed

Root hairs

Fragile parts of cells that grow from the main root

They massively increase the surface area for absorption

Root hair cells Root hair cells (x150)(x150)

Root ‘B’ has had the hairs damaged -

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