Leaf

• Lower & Upper epidermis: transparent cells that act as a protective barrier against injury
• Mesophyll layer: photosynthetic middle layer of leaf, contains chloroplasts
• Chloroplasts: organelle that is main site of photosynthesis (found in the mesophyll)
• Spongy mesophyll: loosely packed photosynthetic cells under the palisade mesophyll (spongy because lots of air space in this layer)
• Palisade mesophyll: tightly packed layer of elongated photosynthetic cells arranged in columns under the epidermis
• Cuticle: outermost layer of the epidermis that is a physical barrier
• Stoma: small openings on the underside of the leaf that allows gasses to enter & exit
• Guard cells: two cells that control the gas exchange and water loss of stoma
• Xylem: vascular tubes that circulate water and nutrients from the roots
• Phloem: vascular tubes that circulate sugars around the plant
• Veins (vascular bundles): contain phloem & xylem