1. Chpt. 9 From Cell to Organism: Focus on Plants  How do multicelled organisms (i.e. plants) use specialized cells to accomplish the same functions as a single cell, but on a larger scale?  How do transport systems move matter in, throughout, and out of plants?  What are the mechanisms that enable plants to respond to their environment?

2. 9.1 Specialized and Organized p 320 - 324 Why do larger organisms have to be multicelled?

3. As cell size increases the SA/vol ratio decreases. It takes too long for materials to diffuse in and out of large cells.

4.  As organisms grow larger they must become multicellular. Different cells become SPECIALIZED to perform specific tasks The organism must be ORGANIZED : OCTOS (organelle, cell, tissue, organ, system)

5. Cell Specialization in Leaves p.320-321 Leaf’s job is????

6. Harness sun’s energy to produce food for the plant (producer, autotroph)

8. X-section of a Leaf

9. Specializations of leaf cells 1. Cuticle: waxy coating - protects leaf from water loss 2. Epidermis: transparent to allow light to pass through to the underlying layer

10. Specializations of leaf cells (cont.) 3. Palisade cells: main cells for photosynthesis: contain LOTS of CHLOROPLASTS

11. Specializations of leaf cells (cont.) 4. Vascular bundle (vein): organizes the 2 transport tissues into “highways” throughout the leaf)

12. Specializations of leaf cells (cont.) 5. Xylem – transports water and minerals from roots to leaves 6. Phloem – transports sugar (food) from leaves to rest of plant

13. Xylem and Phloem in Vascular Bundle

14. Specializations of leaf cells (cont.) 7. Spongy mesophyll: contains chloroplasts and carry out photosynthesis. Loosely packed with many air spaces around them – this structure helps in water and gas exchange with the environments

15. Specializations of leaf cells (cont.) 8. Stomata: openings for gas exchange – CO 2 in for photosynthesis. O 2 out H 2 0 out

16. Specializations of leaf cells (cont.) 9. Guard cells: Regulate the size of the stomata (opening) to control H 2 O loss. The shape of the guard cells change to open or close the stomata.

17. Closed and open stomata

18. Why are most stomata on the underside of the leaf?

19. Organization MUST accompany cell specialization p. 323 O organelles C cells T tissue O organ S system

20. Assignment Complete notes, Do Questions # 1, 12, 18 pg. 350 and # 3, 6, 7 pg. 324