Plant organs
Waxicuticle
Thin, waxy layer covering the leaf.
Reduces water loss.
Protects against pathogens and physical damage.
Can reflect some sunlight.
2. Upper epidermis
Outermost layer on the top of the leaf.
Protects the leaf.
Lets sunlight reach the palisade cells.
Usually has few or no stomata.
Covered by the waxy cuticle.
3. Palisade mesophyll
Located below the upper epidermis.
Cells contain many chloroplasts.
Main site of photosynthesis.
Cells are tightly packed to absorb lots of light.
4. Spongy mesophyll
Below the palisade mesophyll.
Cells are loosely packed with many air spaces.
Allows CO₂ and O₂ to move through the leaf.
Performs some photosynthesis.
Helps water vapour move during transpiration.
5. Vascular bundle
Found in the leaf veins.
Xylem: transports water and minerals; also provides support.
Phloem: transports sugars/food around the plant.