1. Leaves Purpose – photosynthesis Sunlight passes through the cuticle and epidermis into the photosynthetic tissue beneath the leaf surface

2. Leaf structure/Function Mesophyll-photosynthetic tissue. 2 kinds of parenchyma – Palisade mesophyll – column-shaped cells photosynthesis takes place – Spongy mesophyll - irregularly shaped cells surrounded by open space good for gas exchange

4. Functions/Structure Transpiration - loss of water through the stomata Regulated by the guard cells Water in the surrounding cells determines if the guard cells are open or closed.

5. Leaf modifications Modified for purposes other than photosynthesis produce toxins to offer protection Cactus spines – prevent water loss and provide protection Carnivorous plants have leaves that trap insects

6. Leaf modification More modifications Sweet pea tendrils for climbing Overlapping scales to protect buds Colorful bracts of poinsettias Aloe leaves store water Bulb – shortened stem, a flower bud, and immature leaves with food stored in the base