Science-Grade 7 Notes Lesson 2

Chapter 11 Lesson 2

1. Xylem-the tissue that is made up of tubular vessels that transport water and minerals up from the roots throughout the plant.
2. Phloem-a plant tissue that is made up of tubular cells.
3. Cambium-a tissue that produces new xylem and phloem cells.
4. Stomata-the adaption of leaves is small pores in the leaf surfaces.
5. Guard cells-the stomata that open and closes the pores.

Note

• Roots absorb water and minerals, store food and anchor the plant.
• Stems transport the food and water between roots and leaves to support the plant.
• The palisade layer of leaves carries out photosynthesis. Xylem and phloem tissues are located in the spongy layer of the leaf.
• Roots have vascular tissue to move water and minerals from the ground up through the stems to the leaves.
• Each root system must support the plant parts that are above the ground-the stem, branches, and leaves of the tree, for example.
• Roots also store food. When you eat carrots or beets, you eat roots made up of stored food.
• The main functions of a stem are to support the plant and to allow movement of materials between leaves and roots. Some stems also allow them to store food.
• Inside a leaf, a leaf has many different layers, it has a rows of closely packed cells just below the upper epidermis. Palisade cells and the lower epidermis is a layer of loosely arranged cells, the spongy layer, and many air spaces. Xylem and Phloem are located in these air spaces.