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Chapter35

PlantStructure,Growth,andDevelopment

BIOL223

BasicPlantPhylogeny

Monocot/DicotAngiosperms

•  Floweringplants

•  Monocotyledon

•  Oneseedleaf

•  Grasses,Orchids,Bamboo

•  FlowerpetalsinthreesormulHplesofthree

•  Leafveinsparallel

•  Dicotyledon

•  Twoseedleaves

•  Allotherfloweringplants

•  Flowerpartsinfoursorfives

•  LeafveinsreHculate

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Hierarchyoforgans,Hssues,andcells•  PlantshaveHssuesandorganstoo

TheThreeBasicPlantOrgans•  Variablemorphologyofvascularplants

•  ReflectstheirevoluHonasorganisms

•  thatdrawnutrientsfrombelowgroundandaboveground

•  SeenintheiradaptaHonsofspecializedstructuresforthesepurposes

•  Leavesforlight

•  Stomataforair

•  Rootsforwaterandminerals

TheThreeBasicPlantOrgansReproductive shoot (flower)

Apical bud

Node Internode

Apical bud

Shoot system

Vegetative shoot

Leaf Blade Petiole

Axillary bud

Stem

Taproot

Lateral branch roots

Root system

•  Threebasicorgansevolved:

•  Roots,stems,andleaves

•  MadeofthethreeHssuetypes–(Whatarethey?)

•  organizedintotwoorgansystems

•  Rootsystem

•  reliesonsugarproducedbyphotosynthesisintheshootsystem

•  Shootsystem

•  reliesonwaterandmineralsabsorbedbytherootsystem

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Roots

•  Roots

•  MulHcellularorganswith

importantfuncHons:

•  Anchoring

•  AbsorbHon

•  mineralsandwater

•  Storage

•  organicnutrients

•  Taprootsystem

•  onemainverHcalroot

•  givesrisetolateralroots

•  orbranchroots

•  Fibrousrootsystem

•  Seedlessvascularplants(ferns)andmonocots

•  thinlateralroots

•  nomaincentralverHcalroot

•  Adven88ousroots

•  arisefromstemsorleaves

Roots

•  Roothairs

•  Tinybranchesnearendof

roots

•  Microscopicout-foldingof

individualcells

•  PrimarylocaHonofwaterand

mineralabsorpHon

•  Increasedsurfacearea

Roots

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Prop roots

“Strangling” aerial roots

Storage roots

Buttress roots

Pneumatophores

ModifiedRoots

Stems

•  stem(partofshootsystem)

•  organconsisHngof

•  Nodes

•  leafaWachmentpoints

•  LocaHonofaxillary

buds

•  Internodes

•  Stemsegments

betweennodes

•  Axillarybud

•  potenHaltoformalateralshoot,or

branch

•  Apicalbudorterminalbud

•  nearshootHp

•  causeselongaHonofayoung

shoot

•  Apicaldominance

•  helpstomaintaindormancyinmost

axillarybuds

Stems

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Rhizomes

Bulbs

Storage leaves

Stem Stolons

Stolon

Tubers

Modified Stems

Leaves

•  Leaf

•  MainphotosyntheHcorganofmost

vascularplants

•  Generallyconsistof

•  FlaWenedblade

•  Pe8ole

•  Leafstalkwhichjoinsthe

leaftoanodeofthestem

•  Branchesintoveins

(a) Simple leaf

Compound leaf

(b)

Doubly compound leaf

(c)

Petiole Axillary bud

Leaflet

Petiole Axillary bud

Leaflet Petiole Axillary bud

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Tendrils

Spines

Storage leaves

Reproductive leaves

Bracts

Modified Leaves

Dermal,Vascular,andGroundTissues

•  Eachplantorganhas3typesofHssues

•  dermal,vascular,andgroundHssues

•  Eachofthesethreecategoriesformsa8ssuesystem

Dermal tissue

Ground tissue Vascular

tissue

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•  Dermal8ssuesystem

•  Epidermis

•  non-woodyplants

•  Andyoungshootsofwoodyplants

•  barrierofHghtlypackedcells

•  Cu8cle

•  WaxycoaHng

•  helpspreventwaterlossfromtheepidermis

•  Periderm

•  WoodyplantprotecHveHssues

•  replacetheepidermisinolderregionsofstemsandroots

DermalTissueSystem

DermalTissueModificaHons•  Trichomes

•  outgrowthsoftheshootepidermis

•  helpwithinsectdefense

•  Reduceairflow

•  Vascular8ssuesystem

•  long-distancetransport

•  betweenrootsandshoots

•  XylemandPhloem

•  TwovascularHssues

•  Xylem

•  Water/dissolvedmineralsupwardfromrootstoshoots

•  Phloem

•  organicnutrientsfromwheretheyaremadetowheretheyareneeded

VascularTissueSystem

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•  Stele

•  BundleofvascularHssueofastem

orroot

•  Vascularcylinder

•  Singlecentralbundleof

angiospermsrootstele

•  Vascularbundles

•  Stelaofstemsandleaves

•  Smallclustersofxylemandphloem

VascularTissueSystem