1. Plant Structure and Function
Plant Cells and Tissues

2. Plant Cells
Three basic types
Parenchyma
Collenchyma
Sclerenchyma

3. Parenchyma Loosely packed w/large central vacuole
Cubed – shaped or elongated
Involved in
Photosynthesis
Water storage
Nutrition or healing
Bulk of nonwoody plants
Fleshy parts of fruit

4. Collenchyma
Thicker cell walls
Irregular shape
Support for plant

5. Sclerenchyma Thick, even, rigid cell walls
Support and strengthen plant
Dead at maturity
Hardness of shells around nuts

6. Plant Tissue Systems
Dermal
Ground
Vascular

7. Dermal Tissue Forms outside covering Cuticle
Epidermis
Parenchyma cells
Cuticle
Roots develop hair – like extensions
Stomata
Woody stems/roots replaced by dead cork cells (parenchyma)

8. Ground Tissue Surrounded by dermal tissue
All three types of plant cells
Make up majority of nonwoody plants
Main function
Storage
Metabolism
Support

9. Vascular Tissue Surrounded by ground tissue Made up of
Xylem
Conducts water, mineral nutrients from roots upward
Provides structural support
Phloem
Conducts organic compounds, some mineral nutrients
Alive a maturity
Adapted to different environmental conditions
Xylem support and strength
May be absent in aquatic species

10. Plant Growth Flowering plants (Angiosperms) Gymnosperms Dicotyledons
Monocotyledons
Number of cotyledons or seed leaves in a plant embryo
Gymnosperms
Have two or more cotyledons

11. Monocot and Dicots Plant type Embryo Leaves Stems Flower Parts
Examples
Monocots
One cotyledon
Parallel
Venation
Scattered vascular bundles
Usually occur in threes
Lilies, irises, onions, grasses
Dicots
Two cotyledons
Net venation
Radially arranged vascular bundles
Usually occur in fours or fives
Beans, oaks, lettuces, maple, roses, cactuses, carnations

12. Plant Growth Originates in meristems Continuous cell division
Apical meristem (primary growth, length)
Lateral meristem (secondary growth, diameter)
Some monocots grow in length
Intercalary meristems
Located above the base of the leaves or stems (grasses)
Allows plants to regrow quickly after being grazed on

13. Lateral Meristems Gymnosperms and most dicots
Allow stems and roots to increase in diameter
Located outside of stem

14. Lateral Meristem Two types Vascular cambium Cork cambium
Located b/w xylem and phloem
Cork cambium
Located outside phloem
Produces cork
Replaces epidermis
Provides protection and prevents water loss

15. Plants have three kinds of organs
Roots
Stems
Leaves

16. Roots Anchor the plant in the soil
Absorb and transport water and mineral nutrients
Storage for water and organic compounds

17. Types of Roots Taproot Fibrous root system Adventitious roots
Primary root
Rarely more than one – two meters
Fibrous root system
Numerous small roots
Adventitious roots
Specialized roots grow from other places
Leaves and stems
corn and epiphytic orchid (aerial roots)

19. Root Structures Root cap Root hairs
Covers apical meristem
Produces oil
Root hairs
Extensions of epidermal cells
Increase surface area
Dependent on stems and leaves for energy
Store starch

21. Primary Growth in Roots
Increase length through cell division of the apical meristem
Dermal tissue matures for form the epidermis
Ground tissue matures into
Cortex
Endodermis
Large portion of the root is made up of parenchyma cells

23. Endodermis Inner most boundary of cortex
Semipermeable membrane (waxy layer)
Controls the flow of dissolved substances

25. Vascular tissue Makes up innermost core of root Dicots and gymnosperms
Xylem makes up central core
Usually forming an X
Pockets of phloem b/w lobes
Monocots
Xylem occurs in patches that circle the pith (parenchyma)
Phloem occurs b/w the xylem patches

27. Outermost layer of vascular tissues
Pericycle
Form lateral roots