Leaves

1
Leaves
Modified by Georgia Agriculture Education
Curriculum Office September 2005
2
Leaves

• Make food through photosynthesis
• Provide site of gas exchange
• Store food

3
Principal Tissues of the Leaf

• Epidermis
• Cuticle
• Waxy substance covers the leaves and stems
• Waterproof layer that keeps water in plants

4
Principal Tissues of the Leaf

• Epidermis (cont)
• Stomata
• Openings in the epidermis mainly located on
  underside of leaves
• Exchange of gases

5
Principal Tissues of the Leaf

• Epidermis (cont)
• Guard Cells
• Two cells located on each side of stomata
• Open and closes stomata

6
Principal Tissues of the Leaf

• Mesophyll layer
• Palisade mesophyll
• Primary site of photosynthesis
• Spongy mesophyll
• Contains air and chloroplasts
• Site of photosynthesis and gas exchange

7
Principal Tissues of the Leaf

• Veins or vascular bundles
• In spongy mesophyll
• Phloem tissues conduct food from photosynthesis
  to rest of plant
• Xylem tissues conduct water and minerals up to
  cells in leaves and stems