Leaf structure

Plant organs include roots, stems and leaves.

The structure of a leaf has adaptations so that it can carry out photosynthesis effectively.

A leaf needs:

  • a way to transport water to the leaf, and glucose to other parts of the plant
  • a way to exchange carbon dioxide and oxygen
  • the ability to absorb light energy efficiently

Cross section of a leaf

Leaf cross section. Upper and lower epidermis, palisade mesophyll, xylem, vein, pholem, waxy cuticle, air space, spongy mesophyll, guard cells with cholroplasts, gas exchange through stroma, sunlight

Features of leaves and their functions

FeatureFunction
Large surface areaMaximise light absorption
ThinShort distance for carbon dioxide to diffuse into leaf cells
Thin waxy cuticleProtects the leaves without blocking out light
Thin transparent epidermis Allows light to reach the palisade mesophyll cells