Chloroplasts
NonvascularGametangia,
need water to reproduce
Cell walls
Seedless, but vascular
Monocots &
dicots
Adaptations to Terrestrial Life
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•
•
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Stomata(gas exchange)
Cuticle(prevention water loss)
Lignin(support)
Gametangia & seeds
(reproduction)
Pollen(reproduction)
Vascular tissue(support &
transport)-xylem & phloem
Roots(water acquisition,
support)
Seed dispersal mechanisms
General Structure
PlantsGeneral Characteristics
• Terrestrial
• Photosynthetic
• Alternation of generations
charophyte
bryophytes
pteridophytes
gymnosperms
angiosperms
Plant Morphology
Organs  tissues 
Leaves
Stems
Roots
dermal
vascular
ground
meristematic
cells
parenchyma
collenchyma
sclerenchyma
Tissues
1.
Dermal
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Outer covering
Protective
Epidermal cells
(cuticle)
Guard cells
Root hairs
2. Vascular
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•
3.
Transport & support
Xylem & phloem
Ground
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•
Bulk of plant
Photosynthesis,
storage,
support
4. Meristematic
– Embryonic tissuegrows throughout life
of plant
– Roots, shoots,
stem(lateral)
Cell
Types
Found in all 3 tissue types
Thicker cell walls
Heavy lignin
phloem
Found in vascualr bundl
Include
Fibers-bundles, support
Scleroids-nut shells, seed
Tracheids & vessels of
xylem
parenchyma
collenchyma
sclerenchyma
Stems
Functions
• Transport between
roots & leaves
• Storage
• support
Stems-basic structure
• Epidermis
– Cuticle, stoma,
photosynthetic
• Body mostly parenchyma
• Support tissuescollenchyma &
sclerenchyma
• Vascular tissues in bundles
• Scattered
(monocots) or in
rings (dicots)
• Can grow up or out
Monocot stems
scattered
Epidermis______
Dicot Stems
In ring, around pith
Secondary growth-woody dicots only
Produce a
new layer of
xylem &
phloem each
year
Vascular
cambium
divides &
differentiates
Epidermis
becomes cork
cells, part of
bark, along w/
phloem
•Vascular cambiumundifferentiated cells
•Pith & cortex
parenchyma for storage
•Phloem & xylem rays
Transport H2O & nutrients
Laterally
•Primary xylem & phloem
Non-functioning
•Cork cambium
Produces cork cells which
replace epidermis-secrete
suberin & die
•Bark
Phloem(living & dead),
cork cambium & cork
•Periderm
•Cork cambium & cork
Xylem =
oldest
Dead cells & suberin
How does secondary growth happen?
c=vascular cambium cell
D=undifferentiated product of mitosis
X=xylem
P=phloem
Roots
Differentiation
complete
Responsible for
lengthening of root
Protection/lubrication
1st stage of
differentiation
Root Functions
• Anchoring
• Take up water &
minerals
• 1st part to develop
• 2 types
– Taproot(dicot)
– Fibrous(monocot)
•
Basic Structure
• Epidermis(dermal)-covers entire
surface, including hairs
– Absorption, protection
– No cuticle
• Cortex-mainly parenchyma
– No chloroplast, but has storage
plastids
• Stele/vascular cylinder
– Surrounded by endodermis-cells
are highly selective
– Xylem & phloem inside
– Casparian strip
– Pericycle
– Pith(monocots)
Thru cell walls
Thru cytoplasm
Lateral branch from pericycle
Differences between monocots &
dicots
Monocots
__________endodermis
____________pericycle
Dicots
________ epidermis
__________________ cortex
Vascular
Cylinder___
Endodermis___________
Pericycle________________
________________xylem
________________phloem
Leaves
Functions
• Photosynthesis
• Maximize sunlight
exposure
• Gas exchange
• Water conservation
Special Leaf Adaptations
• Specialized photosynthetic
cells
• Shape-most are broad &
flat
• Stomata
• Pointed-water run off
• Needle-shaped-cold &
wind
• Succulents-water storage
•
General
Outer leaf
1. Cuticle(cutin)
2. Epidermis(upper &
lower)
3. Stomata & guard cells
Inner leaf
1. Mesophyll
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Palisade parenchyma
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Spongy parenchyma
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2.
Densely packed,
columnar, upper surface
only
Irregular shapes, large
spaces for gas diffusion
Bundle-sheath cells(C4
plants)
Vascular bundles/veins
Structure
Monocots vs Dicots
• Monocots
– Parallel veins
– No palisade layer
– Vascular bundles
appear scattered under
‘scope
• Dicots
– One large central vein,
smaller veins branching
off (perpendicular)
– Palisade layer distinct
monocot
monocot
dicot
Palisade layer_______
_________spongy
layer
Main vein________
Leaf epidermis
General Structure cont…
fibers