1. A collection of cells that perform a specific function
TISSUES
A collection of cells that perform a specific function

2. Meristems
Unlike animals, plants have permanent regions of cell division
Meristems

3. Meristems Apical Meristems Cell division at tips of roots and stems
Produce primary tissue

4. Meristems Lateral Meristems
Cell division that increases girth of roots and stems
Secondary growth

5. Lateral Meristems
Vascular cambium
Conduction
“Plumbing”

6. Lateral Meristems Vascular cambium Thin cylinder of brick-shaped cells
Majority of growth contributes to increased girth

7. Lateral Meristems Cork cambium
Layer of cells outside phloem layer of vascular cambium
Inside the outer bark

8. Lateral Meristems Intercalary Meristems Develop nodes along stems
Grassy plants
Develop nodes along stems

9. Lateral Meristems Intercalary Meristems Do not contain cork cambium
Vascular bundles

10. Tissues
Simple Tissues
Parenchyma
Collenchyma
Sclerenchyma

11. Simple Tissue Parenchyma cells The most abundant of all cell types
Thin, pliable cell walls
The most abundant of all cell types
Space between parenchyma cells
Intercellular space

12. Simple Tissue Parenchyma cells that contain numerous chloroplasts
Chlorenchyma tissue
Primarily photosynthesis
Parenchyma cells lacking chlorophyll
Food and water storage
Soft, edible parts of fruit and vegetables

13. Simple Tissue Collenchyma cells thicker and longer
Primarily just below the epidermis
Flexible support for growing tissue
Strands of celery

14. Simple Tissue Sclerenchyma cells thickest and toughest cell walls
Impregnated with lignin for support

15. Simple Tissue Sclerenchyma cells form two types of tissues
Form very hard tissue
Sclereids
Gritty texture of pear
Hard shell of nuts

16. Simple Tissue Sclerenchyma cells form two types of tissues
Longer tissue that contain a tiny cavity (lumen)
Fibers

17. Complex Tissue Composed of two or more types of cells Plumbing tissues
Xylem
Phloem

19. DICOT MONOCOT

20. Complex Tissue Xylem Conducts water and minerals from the roots
Transports upward

21. Complex Tissue Xylem Long tubes composed of two tissues Vessels
Large openings at each end allow for water flow
Tracheids
Conduction and support
Smaller cells

22. Complex Tissue Xylem Long tubes composed of two tissues Tracheids
Conduction and support
Smaller cells

23. Complex Tissue
Xylem
Openings along cell walls connect side by side cells
Pits
Lateral flow in trees
Rays

24. Complex Tissue Phloem Conduct water and food in both directions
Primarily down

25. Complex Tissue Phloem Long tubes composed of two tissues Sieve tubes
Similar to xylem vessels
Perforated ends instead of large openings
Sieve plates

26. Complex Tissue Phloem Long tubes composed of two tissues
Companion cells
Similar to xylem tracheids
Support sieve cell functions

27. Complex Tissue Phloem Living sieve tube cells contain callose
Injury will result in callose to plug sieve plate
Callus plug
Plants seal, not heal

28. Xylem and Phloem

29. Complex Tissue
Epidermis
Outermost layer of cells
Skin

30. Complex Tissue Epidermis One cell thick (usually)
Multilayered examples
Orchid aerial roots
Velamen roots

31. Complex Tissue Epidermis Secrete fatty (waxy) substance
Cutin
Protective layer on the outside
Cuticle
Restricts water loss
Resists disease and insects

32. Complex Tissue
Epidermis
Form tubular extensions
Root and foliar hairs

33. Complex Tissue Epidermis Openings along surface Stomata Gas exchange
Transpiration

34. Complex Tissue
Epidermis
Guard cells
Open and close

35. Complex Tissue In woody plants, epidermis sloughed off Periderm
Outer bark
Boxy cork cells

36. Complex Tissue Contain fatty substance to waterproof layer
Suberin
Protects phloem tissue beneath it

37. Complex Tissue Pockets of tissue protruding through periderm
Lenticels
Gas exchange

38. Fig. 4.14

39. Complex Tissue Secretory cells Exude nectar, fragrance or oil
Expel waste from cells

40. Xylem, Phloem, and Transpiration