PLANTS

Evolution of Plants

Monocots and Dicots

The Plant Body

Plant Tissue Systems

• Dermal– Cuticle– Guard Cells

• Vascular– Xylem

• Tracheids• Vessel elements

– Phloem• Sieve-tube members• Companion cells

Xylem

Phloem

Plant Tissue Systems

• Ground –Parenchyma–Collenchyma–Sclerenchyma

Ground Tissue

Plant Growth

• Apical meristems–Primary growth

• Lateral meristems– Secondary growth

Root Structure

• Epidermis– Root hairs

• Cortex• Endodermis– Casparian strip• Suberin

• Vascular cylinder– Pericycle– Xylem,phloem, pith

Primary Root Growth

Primary Stem Structure

• Epidermis– Cutin

• Cortex• Vascular cylinder– Xylem, phloem, pith– Vascular cambium

Secondary Stem Structure

• Vascular cambium– Secondary xylem– Secondary phloem

• Cork cambium– Periderm

Leaf Structure

• Epidermis– Cuticle– Cutin

• Palisade • Spongy• Guard cells– Stomata

• Vascular bundles

Transport in Plants

Transport in Plants

• Osmosis– Root pressure

• Capillary action– Adhesion– Cohesion

• Water potential

Lateral Transport

Xylem Sap Transport• Root pressure– Guttation

• Transpirational pull• Adhesion / Cohesion

Control of Transpiration

Pressure Flow Model

Photoperiodism• Circadian rhythm• Flowering plants– Phytochrome, Florigen

Plant Tropisms

• Gravitropism• Phototropism• Thigmotropism• Peter Boysen-Jensen– Coleoptile

• F.W. Went– Auxin