This preview shows pages 1–2. Sign up to view the full content.
This preview has intentionally blurred sections. Sign up to view the full version.View Full Document
Unformatted text preview: Leaf Structure and Function Photosynthesis- biological process that converts energy into the chemical energy of carbohydrate molecules Leaf Form and Structure Blade- broad, flat portion of a leaf Petiole- stalk that attaches blade to the stem Stipules- leaf like outgrowths usually present in pairs at the base of the petiole Can be simple or compound- axil of axillary buds never develop on leaflets Alternate leaf arrangement- one leaf at each node , area of the stem where one or more leaves are attached Opposite leaf arrangement- 2 leaves grow at each node Whorled leaf arrangement- 3 or more leaves grow at each node Blades may have parallel venation- primary veins , strands of vascular tissue, run approximately parallel to one another (monocots) or netted venation- veins resemble a net (eudicots) Pinnately netted- major veins branching off in succession along the entire length of the midvein (main and central vein of a leaf) Palmately netted- several major veins radiation out from one point Upper epidermis covers upper surface, lower epidermis covers the lower surface Cell walls facing outside are thicker to protect against injury or water loss Cuticle- reduces water loss from exterior walls, composed of cutin Many leaves are covered in hair like structures called trichomes Stomata- minute openings for gas exchange between leaf cells and environment Guard cells- open and close the stomata Subsidiary cells-...
View Full Document