ASDDFSD

1. Roots
Plant organ systems

2. What are the primary functions of
roots?

3. Fibrous and taproot systems

6. Dicots Monocots

7. Root structure

8. Root cap
• Parenchyma
• Perception of
gravity

9. Zone of Maturation - cell differentiation
Protoderm
Ground Meristem
Provascular
Zone of Cell Elongation - cell expansion
Notice how the growing zone has no root hairs or
lateral roots!
Growth among soil particles would result in shear
forces.
Zone of Cell Division - new cells by mitosis
Root Cap - penetration, padding

10. Mucilage Slough Cells

11. Gravitropism
Root Tip Senses Gravity
Auxin Hormone Produced
Auxin Accumulates on Lower
Growth Inhibited on Lower…
Relative to Upper
Root Curves Downward
Water and Mineral Uptake
Root Hairs Increase Surface Area
Root Hairs Secrete Acid (H+)
H+ Cation Exchange w/Minerals
Mineral Uptake into Roots

12. Region of
maturation

14. Mature root structure

15. Monocot root, c.s.

16. Dicot root, c.s.

17. Xylem
Phloem
Endodermis

18. Endodermis regulates mineral
absorption

20. Lateral (branch) roots

21. Endodermis Pericycle

23. Endodermis Pericycle

28. Specialized roots
• Storage roots

29. Propagative roots

30. Pneumatophores

31. Aerial roots

32. Aerial roots – velamen (orchids)

33. Contractile roots

34. Prop roots

35. Root nodules

36. Root nodules

37. Parasitic roots
• Witchweed

38. •Support
•Conduction
•Growth
Stem functions

39. Vascular bundle arrangement
of roots and stems
Roots
Stems
Monocot Dicot

40. Dicot stem anatomy

41. Coleus stem vascular bundles

42. Dicot stem anatomy

43. Secondary growth of dicot stems

44. heartwood sapwood

46. secondary xylem
secondary phloem

47. Annual rings of phloem
phloem
fibers

48. Lenticels
Lenticels

49. Lenticels

50. Specialized stems

51. Cladophyll

52. Thorns

53. Tendrils

54. That’s a big stem!
• Baobab (Adonsonia digitata) grow up to
45 ft. in diameter

55. That’s a big stem!
Redwoods grow up to 350 ft tall; 30 ft. dia.

56. Bristlecone pines
• Oldest organism – 4767 yrs. old