1. Plant Structure, Growth and Development

2. Types of Plants Nonvascular Vascular earliest plants, related to algae
no special vascular tissues devoted to transport
grow close to ground, near water
use spores rather than seeds to reproduce
mosses
liverworts
hornworts
Vascular
have true leaves, stems, roots
vascular tissues: create “tubes” through plants

3. Plant Organization Plants have three levels of organization: Organs
roots, stems, leaves
Tissues
dermal, vascular, ground
Cell Types
Xylem, phloem, parenchyma

4. Plant Structures Root System below ground multifunction Shoot System
stem, branches, leaves, flowers and fruit
vegetative shoots- stems and leaves
floral shoots- bear flowers
above ground

5. Roots Multicellular organs Anchors the plant
Absorbs minerals and water
Stores organic nutrients (sugars/starches)
Root hairs: tiny extensions of epidermal cells
Increase surface area for absorption
Mycorrhizae: fungus + root
symbiotic relationship

6. Root Anatomy

7. Root types Taproots One thick, vertical root
Many lateral (branch) roots
Firmly anchors
Stores food
Fibrous
Mat of thin roots spread just below surface
Shallow
Increased surface area

8. Modified Roots

9. Stems Function: display leaves Consists of:
nodes- where the leaves are attached
internodes- stem segments between nodes
- can be herbaceous (non-woody) or woody
- used for support and conduction
- two kinds of buds
1. axillary buds- found in the angle between the leaf and the stem
2. terminal buds- found at the end of the stem (where most growth occurs)

10. Modified Stems Runner or stolin Rhizome Bulb – underground shoot
Aspen, strawberries, grass
Grow on surface
For asexual reproduction
Rhizome
Iris, ginger, potato, onion
Grow underground
Store food & DNA for new plant
Tuber: end of rhizome
Bulb – underground shoot
Onion
storage leaves

11. Leaves Function: photosynthetic organ Blades: flattened
Petiole: stalk- joins leaf to node of a stem
Most monocots have parallel veins
Most eudicots have branching veins

12. Leaf Anatomy
Layers
Epidermis : two exterior surfaces (upper and lower)
cuticle - waxy coat produced by epidermis
protects against water loss and fungal or bacterial attack
stomata- small openings on the underside of the leaf
- transpiration (gas diffusion)
guard cells swell or relax to close or open stomata, limit gas and water exchange
Mesophyll: layer in between epidermis
- rich in chloroplasts
palisade layer
- chloroplasts in columns just below the epidermal cells
spongy layer cells are less ordered , large intercellular spaces
- facilitate the exchange of CO2 and O2

13. Modified Leaves

14. Plant Tissues
Dermal (epidermis) - protects exterior of plant’s body - forms root hairs Vascular - phloem - xylem Ground (Parenchyma) - non dermal or vascular - pith - cortex

15. Plant Tissues- Dermal Single layer
closely packed cells- cover entire plant
Protect against water loss & invasion by pathogens
Cuticle: waxy layer

16. Plant Tissues- Vascular
Continuous throughout plant
Transports materials between roots & shoots
xylem – water,minerals
roots shoots
phloem- organic nutrients from leaves to where needed

17. Plant Tissues- Ground Tissue (Parenchyma)
Anything that isn’t dermal or vascular
Most common- make up the bulk of soft parts of plants
Function: storage, photosynthesis, support
Pith: inside vascular tissue
Cortex: outside vascular tissue

18. Plant Growth Growth Patterns
Indeterminate growth: plant can grow throughout its life
Determinate growth:
Plant ceases to grow at a certain size
Plant Types:
Annuals complete their life cycle in a year or less
Perennials live for many years

19. Primary and Secondary Growth
Growth Types
Primary and Secondary Growth

20. dome of dividing cells at tip of terminal bud; divide and elongate
Primary Growth (length) vertical growth of apical meristem in roots and shoots
Roots
Shoots
dome of dividing cells at tip of terminal bud; divide and elongate

21. Secondary Growth (diameter)
Occurs in lateral meristem in roots and shoots
Vascular cambium: produces secondary xylem (wood)
Cork cambium: produces tough covering that replaces epidermis
Bark = all tissues outside vascular cambium