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Chloroplasts
Cell walls
NonvascularGametangia, need water to reproduce
Seedless, but vascularMonocots &dicots
Adaptations to Terrestrial Life• 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
gymnosperms
Plant Morphology
Organs tissues cellsLeaves dermal parenchyma
Stems vascular collenchyma
Roots groundsclerenchyma
meristematic
Tissues1. Dermal
• Outer covering
• Protective
• Epidermal cells (cuticle)
• Guard cells
• Root hairs
2. Vascular• Transport & support
• Xylem & phloem
3. Ground• Bulk of plant
• Photosynthesis, storage,
support
Cell Types
Found in all 3 tissue types
phloem
Found in vascualr bundlesThicker cell walls
Heavy ligninInclude Fibers-bundles, supportScleroids-nut shells, seedsTracheids & vessels ofxylem
Stems-basic structure
• Epidermis– Cuticle, stoma,
photosynthetic• Body mostly parenchyma• Support tissues-collenchyma
& sclerenchyma• Vascular tissues in bundles
• Scattered (monocots) or in rings (dicots)
• Can grow up or out
Secondary growth-woody dicots onlyProduce a new layer of xylem & phloem each year
Vascular cambium divides & differentiates
Epidermis becomes cork cells, part of bark, along w/ phloem
•Vascular cambium-undifferentiated cells•Pith & cortexparenchyma for storage•Phloem & xylem raysTransport H2O & nutrientsLaterally•Primary xylem & phloemNon-functioning•Cork cambiumProduces cork cells which replace epidermis-secrete suberin & die•BarkPhloem(living & dead), cork cambium & cork•Periderm•Cork cambium & cork
How does secondary growth happen?
c=vascular cambium cellD=undifferentiated product of mitosisX=xylemP=phloem
Roots
Protection/lubrication1st stage of
differentiation
Responsible for lengthening of root
Differentiationcomplete
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 cytoplasm
Thru cell walls
Dicots________ epidermis
__________________ cortex
VascularCylinder___
________________xylem
________________phloem
Endodermis___________
Pericycle________________
Special Leaf Adaptations
• Specialized photosynthetic cells
• Shape-most are broad & flat
• Stomata
• Pointed-water run off
• Needle-shaped-cold & wind
• Succulents-water storage
•
General StructureOuter leaf1. Cuticle(cutin)2. Epidermis(upper &
lower)3. Stomata & guard cellsInner leaf1. Mesophyll
• Palisade parenchyma• Densely packed,
columnar, upper surface only
• Spongy parenchyma• Irregular shapes, large
spaces for gas diffusion• Bundle-sheath cells(C4
plants)
2. Vascular bundles/veins
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