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PlantNotesPartI–DiversityofPlants

Plants

•  Mul5cellular•  Mostphotosynthe5candcontainchlorophyll•  Cellwallsmadeofcellulose•  Foodstoredasstarch•  Vascular(havingvascular5ssue–trueroots,stems,andleaves)andNonvascular(novascular5ssue)

Whatdoplantsneedtosurvive?

•  Sunlight•  Waterandminerals•  Gasexchange•  Movementofwaterandnutrients

Alterna5onofGenera5ons

•  Mitosisandmeiosisalternatetoproduce2typesofreproduc5vecells–gametesandspores

•  Sporophyte–(n–haploid)sporeproducingplant

•  Gametophyte(2n-diploid)gamete-producingphase

EarlyPlants

•  Thefirstplantsevolvedfromanorganismmuchlikemul5cellulargreenalgae

TypesofPlants:

•  Non-vascular–mosses,hornworts,liverworts•  Seedlessvascular–ferns,horsetails,clubmosses

•  Cone-bearingseedplants–cycads,ginko,conifers

•  Floweringplants-angiosperms

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Distribu5onofPlants NonvascularPlants

•  Lacktransport:ssue(xylemandphloem)•  Smallandrestrictedtomoistterrestrialenvironments

•  No“true”roots,stems,orleaves

•  PhylumBryophyta:Mosses,liverworts,andhornworts

PhylumBrophyta:Mosses,Hornworts,andLiverworts

SeedlessVascularPlants

•  Havevascular:ssue(xylemandphloem)•  Havetrueroots,stems,leavesandstomata•  ReproduceviasporesNOTseeds•  Exhibitalterna:onofgenera:ons

•  Phylums:Filicinophyta(ferns)Sphenophyta(horsetails)Lycophyta(clubmosses)

Ferns,Horsetails,ClubMosses FeaturesofRoots,Stems,andLeaves•  Roots–absorbswateranddissolvednutrients

– Anchorplantsinground

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FeaturesofRoots,Stems,andLeaves

•  Stems– Supportandtransportsystem– Holdupbranches,andtransportwaterandnutrients

FeaturesofRoots,Stems,andLeaves

•  Leaves– Mainphotosynthe5csystems– Vulnerabletowaterloss

•  Haveguardcellsandstomata

Cone-bearingSeedPlants(Gymnosperms)

•  Coneenclosesaplantembryo

•  Phylums:Cycadophyta(Cycads),Gingkophyta(Gingkoes),Coniferophyta(Conifers)

Gymnosperms–Cycads,Ginkos,Conifers

FloweringPlants-AngiospermsRead22.3p.737-749

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PartII

FloweringPlantReproduc5on

FloweringPlants(Angiosperms)

•  Seedsinspecializedreproduc5vestructurescalledflowers

•  Femalereproduc5veovarydevelopsintoafruit

•  Pollina5onusuallyviawindoranimals•  Phylum:Angiospermophyta•  Classes:Monocotyledoneae(monocots)andDicotyledoneae(dicots)

PartsofaFlower

PartsofaFlower

Sepals–green,enclosethebudbeforeitopensandprotecttheflowerwhileitisdeveloping

Petals–o]enbrightlycoloredtoa^ractpollinators

PartsofaFlower

•  Malereproduc5vestructures=stamen,composedof:– Filament–longthinstalkthatsupportstheanther– Anther–loca5onofmeiosisthatproducesmalegametophytes=pollengrains

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PartsofaFlower

•  Femalereproduc5vestructures:– Carpels(pis:ls)–producefemalegemetophytes– Ovary–containsoneormoreovuleswherefemalegemetophytesareproduced

– Style–topoftheovarythatisanarrowstalk– S:gma–s5ckypor5onat5pofstylewherepollengrainsland

LifeCycleofAngiosperm

SeedDevelopmentandgermina5on

•  Seedsmatureinafruit(ovary)thatenclosesthedevelopingseeds

•  Seedscanbedispersedbyanimals,windandwater– Seedsdispersedbyanimalsareusuallycontainedwithinafruit…why?

– Seedsdispersedbywind/waterareusuallylightweight…why?

•  WhyisitadvantageousforseedstobedispersedAWAYfromtheparentplant?

Howisitdispersed?

SeedDormancy

•  Seeddormancy-whenembryoisalive,butnotgrowing

•  Environmentalfactorssuchastemperatureandmoisturecanenddormancyandtriggergermina5on

•  Readp.619–Howcandormancybebeneficial?

Germina5on

•  Germina5on–theearlygrowthstageoftheplantembryo– Seedabsorbswater– Food-storing5ssueswells– Seedcoatcracksandyoungrootemerges

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Germina5on