The simplest ORGAN

ORGANSORGANS - have

one or more FUNCTIONS and composed of SEVERAL TISSUES

ROOTS are the simplest

FUNCTIONS of ROOTSANCHORAGE

FUNCTIONS of ROOTSABSORBING and

CONDUCTING Water and Nutrients

FUNCTIONS of ROOTSFOOD STORAGE

TaprootsFascicled roots

FUNCTIONS of ROOTSFOOD STORAGE in Cortex

FUNCTIONS of ROOTSAll ROOTS are for:

AnchorageAbsorbing and

Conducting Nutrients

Food Storage

Some can REPRODUCE by root cuttings

CLASSIFICATION of ROOTSBased on

ORIGINATION

PRIMARYSECONDARYADVENTITIOUS

CLASSIFICATION of ROOTSBased on TYPE of

ROOT SYSTEM

TaprootFibrousFascicled

ROOT ANATOMYRegion of

Maturation (Differentiation)

Region of Elongation

Meristem Region

Quiescent Zone

Root Cap

ROOT ANATOMYDicots

ROOT ANATOMYMonocots

ROOT ANATOMYSecondary or Lateral root generation

ROOT PHYSIOLOGYWater and Nutrient

CONDUCTION is comprised of THREE ACTIONS

ROOT PRESSURECAPILLARITYTRANSPIRATION

ROOT PHYSIOLOGYROOT

PRESSURE

OSMOSIS

Pathway A – Intercellular Spaces

Pathway B – Root Hairs

ROOT PHYSIOLOGYROOT PRESSURE

Casparian Strip

ROOT PHYSIOLOGYCAPILLARY ACTION (or Capillarity)

Adhesion Cohesion

ROOT PHYSIOLOGYTRANSPIRATIONAL

PULL (or Transpiration)

As WATER EVAPORATES or DIFFUSES from the surface of a leaf, and as cells replace water , the continuous loss of water PULLS it up through plant

SPECIALIZED ROOTS and ASSOCIATIONSPROP ROOTS

CLIMBERS

PNEUMATOPHORES

SPECIALIZED ROOTS and ASSOCIATIONSEPIPHYTES

CONTRACTILE ROOTS

PARASITIC ROOTS

ROOT ASSOCIATIONSMYCORRHIZAL

Associations”Fungus Root”MUTUALISTIC

fungus/plant relationship

Helps absorb WATER and NUTRIENTS for PLANT

Plant provides SUGARS for FUNGUS

ROOT ASSOCIATIONSMYCORRHIZAL Associations

ROOT ASSOCIATIONSBACTERIAL Associations

MUTUALISTIC bacterial/plant relationship

BACTERIA absorbs NITROGEN from atmosphere, and converts it into AMMONIUM (NH4

-) a NUTRIENT for PLANTS

PLANT provides SUGARS for BACTERIA