Leaves: Structure and Function
Main Functions 1. Principle sites of photosynthesis 6CO2 + 6H2O 6O2 + C6H12O6 2. Gas Exchange 3. Water Movement
Structures 1. Blade: flattened area, has a network of veins 2. Petiole: connects leaf to stem
Leaf Scars and Bundle Scars…
Black Walnut What does the leaf scar and bundle scar pattern resemble here?????
Structure 3. VEINS: Vascular bundles Made up of: XYLEM: transports water and minerals PHLOEM: transports food
STRUCTURE 4. Epidermis: Covers entire surface (upper and lower) Waxy transparent layer: Cuticle Protection: Temp Wind Disease
5. Mesophyll: between 2 layers of epidermis, chloroplasts in this layer
STRUCTURE 6. Stomates: Opening in underside of leaf Gas Exchange: Which Gases? CO2 O2 Transpiration: water movement Open in daylight, closed in darkness 7. Guard Cells: Controls stomate opening Filled with water, stoma is open Water is removed, stoma closes
Stomate Open