1. Review What are the three main tissue systems of plants
Compare and Contrast How do the three main functions of a plant’s tissue differ
Form and Function How might the presence of meristems explain the ability of plants to regenerate from cuttings
Infer With your prior knowledge of the circulatory system, write a paragraph comparing and contrasting the structure and function of the vascular system of a plant to the human circulatory system

2. Ch 23 Plant Structure and Function
23.1 Specialized Tissues in Plants

3. Seed Plant Structure
Three principal organs of seed plants are roots, stems, and leaves.

4. Roots Anchor plant in ground
Help prevent erosion
Absorb water and nutrients and transport to rest of plant
Store food
Hold plant upright.

5. Stems Support system for the plant body
Transport system that carries nutrients
Defensive system to protect against predators and disease
Produces leaves and flowers.

6. Leaves Main photosynthetic organs
Regulates water by controlling air exchange.

7. Plant Tissue Systems Three main tissue systems: Dermal Vascular
Ground.

8. Dermal Tissue Protective outer covering of a plant Epidermis
Single layer of cells that makes up the dermal tissue
May have tiny hair like projections on leaves and roots.

9. Vascular Tissue Supports the plant body Transports water and nutrients
Xylem
Phloem
Consist of long, slender cells that connect almost like sections of pipe.

10. Xylem Tracheids Xylem cells
Leave cell walls made of lignin when they die
Openings allow water movement from cell to cell.

11. Xylem Vessel elements Wider than tracheids and are arranged end
After cell dies, cell walls allow water to move freely.

12. Phloem Alive at maturity Transports sugar throughout plant
Sieve tube elements
Arranged end to end with ends having many small holes
Lose nuclei and organelles as they mature
Kept alive by companion cells.

13. Phloem
Companion cells
Supports sieve tube element.

14. Ground Tissue Produces and stores sugars
Contributes to physical support of plant
Neither dermal nor vascular
Three types of ground tissue:
Parenchyma
Collenchyma
Sclerenchyma.

15. Parenchyma Main type of ground tissue Have thin cell walls
Contain many chloroplasts in leaves.

16. Collenchyma Strong, flexible cell walls that help support plant organs
Middle cell wall thickness.

17. Sclerenchyma Extremely thick, rigid cell walls
Makes ground tissue such as seed coats tough and strong.

18. Meristems
Regions of unspecialized cells in which mitosis produces new cells
Found in tips of stems and roots.

19. Apical Meristems Meristem at tip of a stem or root
Cells divide rapidly
Increases plants length.

20. Floral Meristems Produces flowers specialized cells
Develop from apical meristem.