Roots, Stems and Roots, Stems and LeavesLeaves RootsRoots

AbsorptionAbsorption Root hairs increase surface areaRoot hairs increase surface area Mycorrhizae are symbiotic fungi that help plants Mycorrhizae are symbiotic fungi that help plants

absorb nutrients.absorb nutrients. TypesTypes

Fibrous- shallow, increased surface Fibrous- shallow, increased surface area(monocots)area(monocots)

Tap – deep, used for storage(dicots)Tap – deep, used for storage(dicots) Adventitious – climbing roots, above groundAdventitious – climbing roots, above ground

StemsStems PartsParts

NodesNodes InternodesInternodes Auxillary budsAuxillary buds Terminal buds – apical dominanceTerminal buds – apical dominance

Modified StemsModified Stems Stolons – above ground horizontal (strawberries)Stolons – above ground horizontal (strawberries) Rhizomes – below ground horizontal (tubers)Rhizomes – below ground horizontal (tubers)

Modified Shoots

Rhizomes

Stolons of Strawberries

Underground Stem

Tubers

Root Hair Radish

LeavesLeaves

Plant TissuesPlant Tissues Dermal – epidermisDermal – epidermis

ProtectionProtection Layer of tightly packed cellsLayer of tightly packed cells Waxy cuticle prevent water lossWaxy cuticle prevent water loss

VascularVascular Xylem – Tracheids and vessel elementsXylem – Tracheids and vessel elements Phloem – sieve tube members and companion cells.Phloem – sieve tube members and companion cells.

GroundGround Between dermal and vascular tissueBetween dermal and vascular tissue Pith and CortexPith and Cortex Function – photosynthetic, storage and support.Function – photosynthetic, storage and support. Cortex of a dicot stem- both storage and support(large trees)Cortex of a dicot stem- both storage and support(large trees)

Primary and Secondary Walls

Types of Plant TissuesTypes of Plant Tissues

ParenchymalParenchymal

StructureStructure No primary wallNo primary wall Thin flexibleThin flexible Least specialized Least specialized Large vacuolesLarge vacuoles Ground tissue is primarily parenchymal.Ground tissue is primarily parenchymal.

Parenchymal Tissue

CollenchymalCollenchymal Structure Structure

Thicker primary walls than parenchymal cells.Thicker primary walls than parenchymal cells. Primary walls have uneven thicknessPrimary walls have uneven thickness No secondary wall.No secondary wall. Found in young growing herbaceous plant stem.Found in young growing herbaceous plant stem.

FunctionFunction To provide flexible support for growing plantsTo provide flexible support for growing plants

Collencymal Tissue

Sclerencymal TissueSclerencymal Tissue StructureStructure

Thick secondary wallThick secondary wall Much more rigid than collencymal tissue.Much more rigid than collencymal tissue. Dead at maturity and cannot elongateDead at maturity and cannot elongate Deposited in tissues of the plant that are not Deposited in tissues of the plant that are not

growing.growing. Found in bark, wood, nut shells, hempFound in bark, wood, nut shells, hemp

Makes pears gritty.Makes pears gritty. Two types of cells – fiber cells and sclereids.Two types of cells – fiber cells and sclereids.

FunctionFunction SupportSupport

Fiber Cells

Sclereids

Stem StructureStem Structure

Leaf AnatomyLeaf Anatomy

Behold The Stomata!

Leaf Anatomy

Root StructureRoot Structure

Monocot Root

Dicot Root

Plant GrowthPlant Growth

Plants exhibit indeterminate growthPlants exhibit indeterminate growth Grows throughout its entire lifetime.Grows throughout its entire lifetime.

Annuals, biannuals, perenialsAnnuals, biannuals, perenials

Growth Tissue is called Growth Tissue is called Meristematic tissue Meristematic tissue .. Apical MeristemApical Meristem

Primary growth - vertical growthPrimary growth - vertical growth Tips of roots and shootsTips of roots and shoots

Lateral MeristemLateral Meristem Secondary growth - horizontal growthSecondary growth - horizontal growth Rings in a tree can determine its age.Rings in a tree can determine its age.

CambiumsCambiums Vascular Cambium – xylem and phloemVascular Cambium – xylem and phloem Cork Cambium – cork and barkCork Cambium – cork and bark

Pericycle –roots and root hairs.Pericycle –roots and root hairs.

Primary Root Growth

Beware of The Primordial Leaf

Secondary GrowthSecondary Growth

Most Monocots don NOT exhibet secondary Most Monocots don NOT exhibet secondary growth.growth.

Vascular Cambium gives rise new vascular Vascular Cambium gives rise new vascular tissuetissue Xylem towards the center of the stem.Xylem towards the center of the stem.

Older xylem is towards the center of a tree.Older xylem is towards the center of a tree. Older xylem is deadOlder xylem is dead Fills with sap and provides supportFills with sap and provides support

Phloem towards the exterior.Phloem towards the exterior. Older phloem is closer to the bark.Older phloem is closer to the bark.

Cork CambiumCork Cambium Produces cork to exteriorProduces cork to exterior Primary epidermis splits and falls offPrimary epidermis splits and falls off Cork cambium cells secrete a waxy substance Cork cambium cells secrete a waxy substance

called suberin and die.called suberin and die. Cork and cork cambium provide protection Cork and cork cambium provide protection

and are called the and are called the peridermperiderm.. Cork cambium does not change diameter.Cork cambium does not change diameter. Old phloem and bark slough off.Old phloem and bark slough off. Lenitcles are openings in the cork cambium.Lenitcles are openings in the cork cambium.

Secondary Growth

Secondary Growth