1. Roots, Stems, and Leaves

2. Specialized Tissues In Plants
A. Seed Plant Structure
1. Roots
2. Stems
3. Leaves
B. Plant Tissue Systems
C. Dermal Tissue
D. Vascular Tissue
1. Xylem
2. Phloem
E. Ground Tissue
F. Plant Growth and Meristematic Tissue

3. Seed Plant Structure
The cells of seed plants are organized into tissues and organs.
The three main plant organs are roots, stems, and leaves.
Roots absorb water and dissolve nutrients and anchor plants in the ground.
Stems support the plant body and transport materials throughout the plant.
Leaves are the main organs of photosynthesis. They also function in gas exchange.

4. Root, Stem, and Leaf Tissues
Dermal tissue
Vascular tissue
Ground tissue

5. Plant Tissue Systems
Within the roots, stems, and leaves are specialized tissue systems. The three main tissue systems:
Dermal tissue is like the skin of a plant. It protects the plant and prevents water loss.
Vascular tissue consists of xylem (move water throughout the plant) and phloem (moves sugars and other materials throughout the plant).
Ground tissue is made up of all of the cells that lie between dermal and vascular tissues. (made up of 3 kinds of cells)
Parenchyma cells: function in photosynthesis and storage
Collenchyma cells: help support larger plants
Sclerenchyma cells: make ground tissue tough and strong

6. Plant Tissue Systems Cont.
A fourth kind of tissue, meristematic tissue, is responsible for plant growth.
Meristematic tissue is the only plant tissue that produces new cells by mitosis.
The tips of stems and roots are made of meristematic tissue.

7. Concept Map Plant Tissues include Dermal tissue Meristematic tissue
Vascular tissue
Ground tissue
includes
includes
includes
Epidermal cells
Xylem
Phloem
Parenchyma cells
Collenchyma cells
Schlerenchyma cells
includes
includes
Tracheids
Vessel elements
Sieve tube elements
Companion cells

8. Roots The two main types of roots are taproots and fibrous roots.
Taproots: the primary root grows long and thick, while the secondary roots stay small.
Fibrous roots: secondary roots that grow and branch out
Roots have two main functions
To anchor a plant in the ground
To absorb water and dissolved nutrients form the soil

9. Taproots and Fibrous Roots
Taproots (Carrots) Fibrous Roots (Grasses)

10. Cross Section of Plant Root (magnification: 40x)
The Structure of a Root
Epidermis
Root hairs
Phloem
Xylem
Apical meristem
Root cap
Zone of maturation
Zone of elongation
Endodermis
Ground tissue (cortex)
Vascular Cylinder
Ground tissue (cortex)
Epidermis
Endodermis
Vascular cylinder
Cross Section of Plant Root (magnification: 40x)

11. Stems Stems have three important functions
To produce leaves, branches, and flowers
To hold leaves up to the sunlight
To carry water and nutrients between the roots and leaves

12. Plant stems grow in two ways
Comparing Primary and Secondary Growth of Stems
Characteristics
Where It Occurs
Effect on Plant
How It Is Produced
Primary Growth
Secondary Growth
At ends of plants
Increases plant length
By cell division in the apical meristem
In stem
Increases stem width
By cell division in meristems other than the apical meristem

13. Leaves
The structure of a leaf is optimized for absorbing light and carrying out photosynthesis.
To collect sunlight, most leaves have thin, flattened sections called blades.
Plants can lose water out of their leaves as they exchange gases with the air (transpiration).
To prevent major water loss plants allow air in and out of their waterproof covering only through small openings called stomata.
Plants keep their stomata open just enough to allow photosynthesis to take place but not so much that they lose an excessive amount of water.

14. Transpiration A B Evaporation of water molecules out of leaves.
Pull of water molecules upward from the roots.

15. Blades On Leaves

16. The Internal Structure of a Leaf
Cuticle
Veins
Epidermis
Palisade mesophyll
Xylem
Vein
Phloem
Spongy mesophyll
Epidermis
Stoma
Guard cells

17. Transport in Plants Forces of Attraction
Molecules of a similar substance are attracted to one another by a force called cohesion.
Molecules of different substances are attracted to one another by a force called adhesion.

18. Transport In Plants Phloem Xylem Sugar molecules Source cell
Movement of water
Movement of sugar
Sink cell