1. Plant Cells and Tissues
Chapter 23.1

2. Plants are composed of cells which contain:
Cell wall
Central vacuole
Chloroplasts

3. Plant Tissues There are four types of tissues in plants: Dermal tissue
Vascular tissue
Ground tissue
Meristematic tissue

4. Dermal Tissue Also called the epidermis Composed of flattened cells
Protects and covers the body of the plant
Produces the cuticle

5. Located in the Epidermal Layer…
Stomata:
Opening in leaf tissue
Help control water loss from plant
Guard Cells:
Controls the opening/closing of stomata
Trichomes:
Hairlike projections on stem and leaf
Reduces evaporation of water from plant

6. Vascular Tissue
Main function is to transport water, food throughout plant
Two types of vascular tissue
Xylem
Phloem

7. Xylem Transports water from roots to plant Composed of tracheids
Tubular cells tapered at each end

8. Phloem Transports sugars to all parts of the plant
Made up of tubular cells joined end to end

9. Ground Tissue In charge of photosynthesis, storage, and secretion
Found throughout plant

10. Meristematic Tissue Produces most of a plant’s new cells
Located in regions of actively dividing cells

11. Roots, Stems, and Leaves
Chapter 23.2

12. Roots
Anchor, absorb nutrients, contain vascular tissue to transport materials
Can be short or long, thick or thin
Have root hairs
Tiny extensions
Increase surface area of root

13. Stems
Support leaves and flowers, contains vascular tissue to transport materials
Arrangement of vascular tissue:
Monocots: Xylem and phloem scattered throughout stem
Dicots: Xylem and phloem in a circle that form a ring

14. Growth of Stem Primary growth Secondary growth Increase in length
Increase in diameter
Ex: Woody Stem:

15. Leaves Primary function: Photosynthesis
Some leaves joined directly to stem
Example: grass blade
In some leaves, a stalk called a petiole joins the leaf blade to the stem
Simple leaf
Blade that is not divided
Compound leaf
Blade divided into leaflets

16. Transpiration: Leaf venation: Loss of water through the stomata
Patterns of veins in the leaves
Parallel
Pinnate
Palmate

17. Plant Responses
Chapter 23.3

18. Plant Hormones
Plants have hormones that regulate growth and development
Auxins and Gibberellins (2 hormones) that promote growth in plants

19. Plant Responses Why do stems grow up and roots grow down? Tropism
Plant’s response to an external stimulus
Phototropism
Plant growth toward light
Gravitropism
Plant growth in response to gravity