1. Part 3 Roots, Stems & Leaves
Plant Notes
Part 3
Roots, Stems & Leaves

2. The structure of a plant contains a shoot system and a root system.
Structure of Plants
The structure of a plant contains a shoot system and a root system.

3. Plant Tissue Systems Plants consist of 3 main tissue systems:
Dermal tissue
Vascular tissue
Ground tissue

4. Plant Tissue Systems
DERMAL TISSUE:
The outer covering of a plant

5. Plant Tissue Systems VASCULAR TISSUE:
Forms the transport systems within the plant
Includes xylem & phloem

6. Plant Tissue Systems GROUND TISSUE:
Cells that lie between the dermal and vascular tissues.

7. Types & Functions of Roots
The root system includes those parts of the plant below ground, such as the roots, tubers, and rhizomes.
Taproots are found mainly in dicots.
Fibrous root systems are found mainly in monocots.
The function of all roots is to anchor the plant in to the ground & absorb water and nutrients from the soil.

8. Stem Structure & Functions

9. Stem Structure & Functions
In general, stems have 3 important functions:
1.) to produce leaves, branches & flowers
2.) to hold the leaves upright towards
the sun
3.) to transport substances between roots & leaves

10. Parts of a Stem

11. Types of Stems Recall from your previous plant notes:
Herbaceous – soft, green
Woody – dark, rigid

12. Stem Arrangements
The leaves on a plant have one of the following 3 arrangements:
ALTERNATE
WHORLED
OPPOSITE

13. Stem Growth
Primary growth of a stem occurs when there is an increase in plant growth from the tips of the roots and the shoots.
In other words, the plant grows in height.

14. Stem Growth
Secondary growth of a stem occurs when there is an increase in the width of a plant.

15. Modified Stems
Many kinds of plants have modified stems that store food.
Tubers, rhizomes, bulbs and corms are all types of modified stems that can remain dormant during cold or dry periods until favorable conditions return.
TUBER
ONION
IRIS

16. Leaves Leaves are the primary photosynthetic organ of a plant
The structure of a leaf is optimized for absorbing light and carrying out photosynthesis, as well as performing transpiration (water loss) and gas exchange by giving off O2 and taking in CO2.

17. Leaves
Leaves may differ greatly in shape, arrangement, margin and venation, but the structural features of most leaves are the same.

18. Leaf Arrangements

19. Leaf Shapes

20. Leaf Margins

21. Leaf Venation

22. Anatomy of a Leaf
The leaf provides food for the rest of the plant through the process of photosynthesis.
The outermost layer of the leaf is the epidermis, which is protected by the waxy coating of the cuticle.
Guard cells implanted in the epidermis form pores, known as stomata, through which water, oxygen, and carbon dioxide pass.

23. Leaf Structure & Function
Leaves depend on stomata, which are pore-like openings on the underside of each leaf that allow CO2 and O2 to diffuse into & out of the leaf.
Plants can regulate the opening and closing of their stomata to balance water loss with the rates of photosynthesis.

24. Leaf Structure & Function

25. Lets see what you learned….
REVIEW>>>REVIEW>>>REVIEW

26. Types of leaves ______ = one entire blade
______= (divided leaf blade = leaflets)
Palmately – leaflets come together at a
central point
Pinnately – leaflets attach to the petiole in a pattern resembling a feather

27. Types of leaves Simple = one entire blade
_____= (divided leaf blade = leaflets)
Palmately – leaflets come together at a
central point
Pinnately – leaflets attach to the petiole in a pattern resembling a feather

28. Types of leaves Simple = one entire blade
Compound (divided leaf blade = leaflets)
Palmately – leaflets come together at a
central point
Pinnately – leaflets attach to the petiole in a pattern resembling a feather

29. Leaf Margin
_______
______________
______

30. Leaf Margin
Smooth
_____________
______

31. Leaf Margin
Smooth
Toothed (serrated)
______

32. Leaf Margin
Smooth
Toothed (serrated)
Lobed

33. Leaf Venation ___________ – Monocots __________________ –Dicots
Palmate venation
Pinnate venation

34. Leaf Venation Parallel veins – Monocots __________________ –Dicots
Palmate venation
Pinnate venation

35. Leaf Venation Parallel veins – Monocots
Netted (branched) veins –Dicots
Palmate venation
Pinnate venation

36. ______Leaf

37. Simple Leaf

38. __________Leaf

39. Compound Leaf

40. Carnivorous Leaves Did you know???
The 2 lobes of a Venus's-flytrap leaf form a deceptively safe and attractive landing place for insects and other animals.
Less than a second after this frog trips the trigger bristles on the inside surface of the leaf, the lobes close enough to trap him below interlocking spines.
If sensory organs determine that the frog contains protein, the leaf closes further and the plant's digestive enzymes start to flow.