1. Chapter 35

2.  Cells make up tissues and tissues make up organs.  Plants have 3 main organs:  Roots  Stems  Leaves

3.  Used to anchor vascular plants  Absorbs minerals and water  Stores organic nutrients  The main vertical root is the taproot, which has branches called lateral roots  Root tips do most absorption  Tiny root hairs increase the surface area of the root

4.  Stems have nodes (where leaves attach) and internodes (in between leaves)  Shoots form from axillary buds that grow from where leaves attach to stems  Modified stems include: rhizomes (ginger or garlic), tubers (potatoes), bulbs (onions)

5.  Leaves are where sunlight is absorbed by chlorophyll for photosynthesis  Consist of a blade and a stalk (petiole)  Veins are the vascular tissue (xylem and phloem)  Modified leaves include tendrils, spines, bracts (poinsettia), and cacti storage leaves.

6.  Stomata are openings in leaves for gas exchange  Guard cells control whether stomata are open or closed  Mesophyll is the tissue where photosynthesis occurs  Xylem and phloem are in the mesophyll, and are enclosed by bundle sheath cells

7.  Dermal: outer protective covering; includes cuticle, a waxy coating that prevents water loss  Vascular: xylem and phloem  Ground: used for storage, called pith or cortex

8.  Parenchyma Cells: “typical plant cells”  Collenchyma Cells: support young parts of plant shoots  Sclerenchyma Cells: Mature cells, functionally dead, used for support

9.  Meristems generate cells for new organs  Plants grow throughout their lives, but do die:  Annuals: complete their life cycles in a year or less; grains, beans, wildflowers  Biennials: live 2 years; beets, carrots  Perennials: live many years: trees, shrubs, grasses

10.  Roots and shoots grow from the tips (apical meristems)  The root tip is covered by the root cap (protection)  Zone of cell division: where mitosis occurs  Zone of elongation: root cells elongate  Zone of maturation: cells differentiate and become mature

11.  Tissues called vascular cambium and cork cambium produces secondary xylem and phloem which turns into wood  Rings of trees build up as trees age. The center is called heartwood; outer layers are called sapwood.  Bark is used for protection and has phloem in it