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The Leaf of a Flowering Plant. Factory of Photosynthesis. Leaf Functions. Carries on Photosynthesis Stores food Limited capability of reproduction Regulates transpiration. External Leaf Anatomy. Blade: The flattened part of the leaf. Margin: The edge of the blade.
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The Leaf of a Flowering Plant Factory of Photosynthesis
Leaf Functions • Carries on Photosynthesis • Stores food • Limited capability of reproduction • Regulates transpiration.
External Leaf Anatomy • Blade: The flattened part of the leaf. • Margin: The edge of the blade. • Petiole: Connects the blade with the stem. • Vein: xylem, phloem, and connective tissue.
Leaf Type • Simple Leaf: The blade is one complete structure. • Compound Leaf: The blade is divided into smaller units called leaflets.
Leaf Venation • Netted: One main vein with many branching ones off to the sides. (Dicots) • Parallel: Many main veins running along the length of the blade. (Monocots)
Internal Leaf Anatomy • Epidermis • Cuticle • Palisade Mesophyll (chloroplasts) • Spongy Mesophyll • Vein (xylem and phloem) • Air Spaces • Lower Epidermis • Stomata • Guard cells Upper Epidermis Palaside Mesophyll Xylem Phloem Air Space Stoma Guard Cells
Stomata • Guard cells regulate the size of the stoma. • K+ (potassium ions) enter the cells causing them to fill with water. • This opens the stoma when they become turgid. • A loss of K+ causes the opposite to occur, and they close when they become flaccid. Stomata Control Open The Cells are Turgid Closed The Cells are Flaccid