Biology 10H - Cross Section of a Leaf

Lower epidermis

The outer most tissue on the underside of the leaf that contains the stomata.

Upper epidermis

Outer most tissue on upper side of leaf.

Palisade layer

Part of mesophyll in which cells are tightly packed together; Photosynthesis occurs here (contains lots of chloroplasts)

Cuticle

Waxy covering that protects plant from water loss and external environmental stresses.

Stomata

Opening between guard cells that allows gases (carbon dioxide, oxygen gas, and water vapor) to pass through.

Guard cells

Cells that control the opening and closing of the stomata.

Vein (fibrovascular bundle)

Supplies structural support for the leaf and contains the xylem and phloem.

Spongy layer

Part of the mesophyll that contains loosely packed cells with many air spaces.

Air space

Space in the spongy layer that contains gases.

Xylem

Tissue in vein that transports water and dissolved minerals upward in the plant.

Phloem

Tissue in vein that transports food/glucose downward in the plant.

Chloroplast

Organelle of a leaf cell that contain chlorophyll and is where photosynthesis occurs.

Mesophyll

Middle tissue of a leaf where photosynthesis takes place.