Plant org lab tz

1. Plant Tissue Systems
 Ground tissue system
• Photosynthesis, storage, and structural support of
other tissues
 Vascular tissue system
• Distributes absorbed water and mineral ions and
products of photosynthesis
 Dermal tissue system
• Covers and protects exposed plant surfaces

2. Body Plan: Tomato Plant
•Shoot system: above
ground
•Stems, leaves, flowers
•Root system: below
ground

3. Apical and Lateral Meristems
•Apical meristem: located
at tips of shoots and roots
•Primary growth
•Lengthening
•Lots of mitosis
•Lateral meristem:
secondary growth
•Thickening

4. Vascular Tissues
•Xylem: transports water
•Two cell types: tracheids
and vessel elements
•Hollow, nonliving
•Phloem: transports sugars
•Cells called sieve tubes
•Living

5. Dermal Tissues
 Epidermis
• Usually a single outer layer of cells that secrete a
waxy, protective cuticle
• May contain specialized cells that form stomata
for gas exchange

6. Eudicots and Monocots
 Flowering plants are divided into two classes
with tissues organized into different patterns
 Eudicots have two cotyledons (seed leaves)
• Netlike leaf veins
• Floral parts in multiples of 4 and 5
 Monocots have one cotyledon
• Parallel leaf veins
• Floral parts in multiples of 3

7. Inside the Stem
 Vascular bundles
• Multistranded cords of vascular tissues threaded
lengthwise through ground tissues of all shoots
 Two distinct patterns of vascular bundles
• Eudicot stems: Cylinders run parallel with stem,
divide ground tissue into cortex and pith
• Monocot stems: Bundles distributed throughout
ground tissue

8. Root Structures
 Divided into four
general regions
• Root Cap: protects root
as it lengthens
• Region of Cell
Division: apical
meristem
• Region of Elongation:
cells lengthen and widen
• Region of Maturation:
mature cells differentiate
into different types
•Root hairs: increase
the surface area for water
and nutrient uptake
•Derived from epidermis

9. Internal Root Structures
 Epidermis: covers exposed surfaces
 Cortex: cells adjacent to the epidermis
• Used for food storage
 Vascular tissues: xylem
and phloem
• Form the vascular cylinder
 Endodermis: single cell layer
around the vascular tissues
• Aids in mineral/water exchange
 Pericycle: undifferentiated cells
• Source of new lateral roots

10. Eudicot and Monocot Root Structures
You will look at cross section slides of a monocot and a
eudicot root.
Notice the star shape xylem and phloem in between the points
on the eudicot
Look for the pith in the monocot, used for food storage.

11. Root Systems
Taproot Fibrous root

12. Modified Stems
 Many plants have modified stem structures that
function in storage or reproduction
• Stolons (reproductive runners)
• Rhizomes (main underground storage stems)
• Bulbs (layered underground stems)
• Corms (solid underground storage stems)
• Tubers (stolons thickened for storage)

13. Leaf Shapes
•Simple leaf: single blade
•Compound leaf: blade
with leaflets
•Palmately: leaflets
attached at one point
•Pinnately: leaflets
attached at intervals

14. Leaf Structure
•Epidermis: outermost
layer of cells
•Lower and upper
•Cuticle: waxy, protect,
conserve H2O
•Palisade mesophyll:
upper, many
chloroplasts
•Spongy mesophyll:
lower, air spaces
•Stomata: openings for
gas exchange
•Guard cells: surround
stomata and control

15. Vein Patterns in Flowering Plants