1. Plants: Structure and Function

2. A protective covering that surrounds the seed
Makes seeds.
Makes the plant's food.
Carries water and food to the rest of the plant.
Anchor the plant in place and absorb water and other minerals from the soil.

3. Grouped by Characteristics
Vascular
Three main parts: roots, stems and leaves
Roots can be different sizes:
Fibrous and tap roots
Storage roots: beets, carrots, sweet potatoes and turnips
Roots have different functions: anchoring the plant, taking in water and minerals, and store food.
Nonvascular
Simple; most grow in moist places
No vascular tissues.
Includes mosses, liverworts, hornworts and algae

4. Vascular Plants: Stems
Function of Stems
Support, transport of water & food
Most stems grow upward
Some stems grow sideward
Types of stems
Green
Woody
Transport of materials
Xylem & phloem

5. Vascular Plants: Leaves
Leaves come in variety of shapes and sizes
Leaves are arranged in different ways

6. Plant Tissue Groups

7. Plant Tissues
A tissue is a group of cells organized to form a functional unit or a structural unit
Plants have 3 tissue systems:
Ground tissue
Vascular tissue (xylem and phloem)
Dermal tissue (exterior)

9. Ground Tissue Parenchyma Collenchyma Sclerenchyma
Found throughout the plant, these tissues perform important functions like photosynthesis, food storage, and secretion
Collenchyma
Structural support in herbaceous plants
Found just under the stem epidermis and along leaf veins
Sclerenchyma
Hard structural support (trees)
May be alive or dead and still function structurally
One type of sclerenchyma is fiber (wood)

10. Dermal
Epidermis - outermost layer composed of single layer of ground parenchyma cells
Periderm - many layers thick, found on woody plants, replaces epidermis, parenchyma cells

11. Xylem and Phloem Both add structural support
Xylem - conducts water and minerals, long tapering cells that act as pipes of a sort
Phloem - conducts food

12. Root Structure

13. Root Structure Root Cap Apical meristem Zone of Elongation
Protects the growing tip of the root and helps it grow down
Apical meristem
Root tip where growth occurs
Zone of Elongation
Area in plant roots where recently produced cells grow and elongate prior to differentiation.
Zone of Maturation
Cells have differentiated into the different plant tissues
Root Hairs
Help absorb water and nutrients
Vascular Cylinder
The center of the root occupied by a core of vascular tissue (xylem and phloem)

14. Vascular Cylinder Xylem Phloem
Tissue whose basic function is to transport water but will transport some minerals
Phloem
Tissue whose basic function is to transport sugars throughout the plant

15. Water Transport in the Root

16. Internal Leaf Structure

17. Internal Structure Cuticle Epidermis Mesophyll
Protective covering on the leaf
Epidermis
Out layer of cells that helps to protect from water loss, regulate gas exchange, and secrete metabolic compounds
Stomata are found in the leaf epidermis
Mesophyll
Interior of the leaf, specialized for photosynthesis

19. What Prevents Water from Leaving the Plant?

20. What Prevents Water from Leaving the Plant?
What type of environmental conditions would increase transpiration?
Sunny, warm, dry, windy weather all increase evaporation
Guard cells control stomata
Stomata = pores in leaves
Keep stomata open during day and closed at night
How do they open? Close?
Ions move into vacuoles creating concentration gradient
Water moves into vacuoles via osmosis
Reverse gradient, lose water

23. Tree Structure

24. The Big Question: How does water move from roots to leaves?

25. Transpiration moves water up xylem vessels

26. Transpiration moves water up xylem vessels

27. Transpiration moves water up xylem vessels

28. Transpiration Moves Water Up Xylem Vessels
Transpiration exerts an upward pull
What is responsible for this pull?
Diffusion! And a bonus – no energy required!!
The “string” of water is held together by cohesion and is helped upward by adhesion
Is known as “transpiration-cohesion-adhesion mechanism”