1. Exam #2 M 3/8 in class
Q&A Fri. 3/5 from 4-6pm in WRW 102

2. Plants grow and reproduce, as well as, respond to the environment.

3. Plants grow and reproduce, respond to the environment… today- transport

4. Types of Plant Cells:
defined by function and cell wall

5. Plant cell walls are mostly made of cellulose
Fig 6.9

6. Cellulose is made of glucose
Fig 5.7

7. Cellulose is made of glucose
Fig 5.8

8. Only a few prokaryotes and fungi can digest cellulose
Fig 5.9

9. Cell walls contain cellulose, pectins, proteins...

10. Parenchyma cells- most common cells; primary cell walls
Fig 35.10
60 m

11. Fig 35.17
Parenchyma in a stem

12. Collenchyma cells- unevenly thickened cell walls; flexible support
Fig 35.10
80 m

13. Collenchyma in a leaf

14. Sclerenchyma cells- Thickened secondary walls (inside primary wall); with lignin; rigid
Fig 35.10
5 m
25 m

15. 100 m
Water conducting cells of Xylem: vessels and tracheids (types of sclerenchyma)
Fig 35.10

16. Sugar conducting cells of Phloem: sieve-tubes and companion cells
Fig 35.10
30 m
15 m

17. Fig 36.2
Plants transport water in xylem, sugar in phloem, plus minerals and hormones…

18. Water travels from ground out through stomata via xylem
Fig 36.2
Water travels from ground out through stomata via xylem

19. The exit of water through stomata is accompanied by gas exchange
Fig 36.2
The exit of water through stomata is accompanied by gas exchange

20. Fig 36.2
Sunlight powers photosynthesis and these sugars are transported via phloem

21. Phloem transport is from source to sink.
Fig 36.20
Phloem transport is from source to sink.

22. Sugar is loaded at sources and unloaded at sinks...
Fig 36.20
source: leaf
Sugar is loaded at sources and unloaded at sinks...
consuming ATP
sink: root, flower, emerging leaf etc…

23. Source and sink locations vary...

24. The direction of Phloem transport is versatile.

25. Much of plant support comes from turgor pressure.
Fig 36.10
Much of plant support comes from turgor pressure.

26. CB 36.15
Water moves from the ground through roots into the shoot and out stomata in the leaves.

27. In roots the vascular bundle is in the center
Fig 35.13
In roots the vascular bundle is in the center

28. Fig 36.11
Plant cell to cell transport can occur by two pathways: symplastic and apoplastic
plasmodesmata

29. Fig 36.12
The casparian strip of the endodermis keeps water from entering the xylem via a purely apoplastic route.

30. What moves the water through the xylem?

31. Stomata control entry of CO2 and exit of H2O from plant leaves
Fig 36.14
Stomata

32. Stomata on the underside of a leaf

33. Guard cell opening is regulated by turgor
Fig 36.17
Guard cell opening is regulated by turgor

34. Fig 36.15
What moves the water through the xylem? Transpiration, Adhesion, Cohesion, and Tension

35. water transport limits plant growth

36. More xylem is needed for more water transport: secondary growth
phloem
xylem

37. Xylem is tough, and full of lignin- inhibits the ability to use plants to produce biofuels
phloem
xylem

38. Exam #2 M 3/8 in class
Q&A Fri. 3/5 from 4-6pm in WRW 102