Introduction to plants

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IntroductioIntroductio

n to the n to the Plant Plant

KingdomKingdomcopyright cmassengalecopyright cmassengale

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Early Early AncestorsAncestors

Aquatic to Aquatic to Terrestrial LifeTerrestrial Life

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Aquatic AncestorAquatic Ancestor Closest living Closest living

speciesspecies to a to a possible land possible land plant ancestorplant ancestor

Group of Group of green green algaealgae

Called Called CharyophyceanCharyophyceanss CharaChara


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Algae & Land Plant Algae & Land Plant SimilaritiesSimilarities

Both contain Both contain chlorophylls chlorophylls aa and and bb Have Have chloroplastschloroplasts with stacks of with stacks of

thylakoidsthylakoids Store Store starchstarch in in plastidsplastids CelluloseCellulose in in cell wallscell walls Go through Go through Alternation of Alternation of

Generations Generations life Cyclelife Cyclecopyright cmassengalecopyright cmassengale

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Terrestrial HabitatTerrestrial Habitat

Aquatic Aquatic HabitatHabitat


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Living in Aquatic Living in Aquatic EnvironmentsEnvironments

Plants surrounded by water so Plants surrounded by water so don’t dry outdon’t dry out

Sperm swimsSperm swims to egg to egg Water supportsWater supports plant plant Plants stay in upper surface Plants stay in upper surface

near lightnear light AbsorbAbsorb nutrients nutrients from thefrom the H H22OO


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Plant Adaptations to Plant Adaptations to LandLand

Problems:Problems: Need mineralsNeed minerals GravityGravity Increase in Increase in

Height for Height for LightLight

Adaptations for Adaptations for Drier Drier environmentenvironment

ReproductionReproduction

Solutions:Solutions: RootsRoots absorb H absorb H22O & O &

mineralsminerals Lignin & celluloseLignin & cellulose in in

cell wallscell walls Vascular Vascular Transport Transport

SystemSystem Waxy cuticleWaxy cuticle & &

stomatastomata with guard with guard cellscells

Pollen Pollen containing containing spermspermcopyright cmassengalecopyright cmassengale

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How Are Plants How Are Plants All Alike?All Alike?


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Plant CharacteristicsPlant Characteristics MulticellularMulticellular AutotrophicAutotrophic (photosynthesis) (photosynthesis) Chlorophylls Chlorophylls aa and and bb in thylakoid in thylakoid

membranesmembranes Surrounded by Surrounded by cell wallscell walls containing containing

cellulose (polysaccharide)cellulose (polysaccharide) Store reserve food as Store reserve food as amylose amylose

(starch)(starch)


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Plant ReproductionPlant Reproduction Alternation of generations Alternation of generations life life

cyclecycle Diploid (2n) Diploid (2n) sporophytesporophyte stage stage Haploid (1n) Haploid (1n) gametophytegametophyte stage stage Produce Produce multicellular embryomulticellular embryo

protectedprotected inside multicellular inside multicellular haploid haploid (gametophyte egg sac)(gametophyte egg sac) tissuetissue


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Plant ReproductionPlant Reproduction Diploid (2n) Diploid (2n) sporophytesporophyte stage stage

produces produces haploid sporeshaploid spores by by meiosismeiosis

Haploid spores undergo Haploid spores undergo mitosismitosis to produce to produce gametophytegametophyte stage stage

Gametophyte makes Gametophyte makes gametes gametes (eggs and sperm) (eggs and sperm) by by meiosismeiosis

ZygoteZygote (2n) produces the new (2n) produces the new sporophytesporophyte


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Alternation of Alternation of GenerationsGenerations

2n 2n SporophyteSporophyte

2n 2n gametophytegametophyte

1n 1n pollenpollen

Ovary with Ovary with 1n ovules 1n ovules (eggs)(eggs)

2n seed 2n seed with plant with plant embryoembryo

SporophySporophytete

GametophyGametophytete


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Plant Plant

DivisionsDivisions


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TaxonomyTaxonomy Plants are divided Plants are divided

into into twotwo groupsgroups Based on the Based on the

presence or presence or absenceabsence of an of an internal transport internal transport systemsystem for water for water and dissolved and dissolved materialsmaterials

Called Called Vascular Vascular SystemSystem

VasculaVascular r BundleBundless


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Vascular SystemVascular System XylemXylem tissue carries tissue carries waterwater and and

mineralsminerals upward from the upward from the rootsroots

PhloemPhloem tissue carries tissue carries sugarssugars made by photosynthesis from made by photosynthesis from the leaves to where they will the leaves to where they will be stored or usedbe stored or used

SapSap is the fluid carried inside is the fluid carried inside the xylem or phloemthe xylem or phloem


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Nonvascular PlantsNonvascular Plants Do not have Do not have

vascular tissue vascular tissue for for supportsupport or or conduction of conduction of materialsmaterials

Called Called BryophytesBryophytes

Require a Require a constantly moist constantly moist environmentenvironment

Moss Gametophytes & Moss Gametophytes & SporophytesSporophytes

Sporophyte stageSporophyte stage

GametophyGametophyte Stagete Stage


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Nonvascular PlantsNonvascular Plants Plants can’t grow as tallPlants can’t grow as tall Cells must be in Cells must be in direct direct

contact with moisturecontact with moisture Materials move by Materials move by

diffusiondiffusion cell-to-cell cell-to-cell Sperm must Sperm must swim to eggswim to egg

through water dropletsthrough water dropletscopyright cmassengalecopyright cmassengale

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Nonvascular PlantsNonvascular Plants Includes mosses Includes mosses (Bryophyta)(Bryophyta), ,

liverworts liverworts (Hepatophyta)(Hepatophyta), and , and hornworts hornworts (Antherophyta)(Antherophyta)

LiverwortsLiverworts HornwortsHornwortscopyright cmassengalecopyright cmassengale

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Main Parts of Vascular Main Parts of Vascular PlantsPlants

ShootsShoots-Found above ground-Found above ground-Have leaves attached-Have leaves attached- Photosynthetic part - Photosynthetic part

of plantof plant RootsRoots

-Found below ground-Found below ground-Absorb water & minerals-Absorb water & minerals-Anchor the plant-Anchor the plant


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Vascular PlantsVascular Plants Also called Also called

TracheophytesTracheophytes Subdivided into Subdivided into

two groups -- two groups -- Seedless Seedless vascular plantsvascular plants and and Seed-Seed-bearing bearing vascular plantsvascular plants

Club MossClub Mosscopyright cmassengalecopyright cmassengale

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Seedless Vascular PlantsSeedless Vascular Plants Includes club moss Includes club moss (Lycophyta)(Lycophyta), ,

horsetails horsetails (Sphenophyta)(Sphenophyta), whisk , whisk ferns ferns (Psilophyta)(Psilophyta), and ferns , and ferns (Pterophyta)(Pterophyta)

HorsetailsHorsetailsWhisk fernsWhisk ferns copyright cmassengalecopyright cmassengale

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Seed-Producing Vascular Seed-Producing Vascular PlantsPlants

Includes two groups – Includes two groups – GymnospermsGymnosperms and and AngiospermsAngiosperms

GymnospermsGymnosperms have have naked naked seedsseeds in in conescones

AngiospermsAngiosperms have have flowers that flowers that produce seeds produce seeds to attract to attract pollinators and produce seedspollinators and produce seeds


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GymnospermsGymnosperms ConiferophytaConiferophyta are are

known as conifersknown as conifers Includes pine, Includes pine,

cedar, spruce, cedar, spruce, and firand fir

CycadophytaCycadophyta – – cycadscycads

GinkgophytaGinkgophyta - - ginkgoginkgo

GinkgGinkgoo

CycaCycadd


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GymnospermGymnospermss

Contains the Contains the oldest living oldest living plant – plant – Bristle Bristle cone pinecone pine

Contains the Contains the tallest living tallest living plant – plant – Sequoia or Sequoia or redwoodredwood


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AngiospermsAngiosperms Flowering plantsFlowering plants SeedsSeeds are formed when an are formed when an

egg or ovuleegg or ovule is fertilized is fertilized by by pollenpollen in the ovary in the ovary

OvaryOvary is within a flower is within a flower Flower contains the male Flower contains the male

(stamen)(stamen) and/or female and/or female (ovaries)(ovaries) parts of the plant parts of the plant

FruitsFruits are frequently are frequently produced from these produced from these ripened ovaries (ripened ovaries (help help disperse seeds)disperse seeds)


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AngiospermsAngiosperms Division Division AnthophytaAnthophyta Subdivided into two groups – Subdivided into two groups –

Monocots and DicotsMonocots and Dicots MonocotsMonocots have a single seed have a single seed

cotyledoncotyledon DicotsDicots have two seed have two seed

cotyledonscotyledonscopyright cmassengalecopyright cmassengale

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MonocotsMonocots ParallelParallel

venation in venation in leavesleaves

Flower parts in Flower parts in multiples of 3multiples of 3

Vascular Vascular tissue tissue scatteredscattered in in cross section cross section of stemof stem


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DicotsDicots Net venationNet venation

in leavesin leaves Flower parts in Flower parts in

multiples of 4 multiples of 4 or 5or 5

Vascular Vascular tissue tissue in ringsin rings in cross in cross section of section of stemstem


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Plant UsesPlant Uses


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Why We Can’t do Why We Can’t do Without Plants!Without Plants!

Produce oxygen for the Produce oxygen for the atmosphereatmosphere

Produce lumber for buildingProduce lumber for building Provide homes and food for Provide homes and food for

many organismsmany organisms Prevent erosionPrevent erosion Used for foodUsed for food


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More Reasons We Can’t More Reasons We Can’t do Without Plants!do Without Plants!

Produce wood pulp for paper Produce wood pulp for paper productsproducts

Source of many medicinesSource of many medicines Ornamental and shade for Ornamental and shade for

yardsyards Fibers such as cotton for fabricFibers such as cotton for fabric DyesDyes


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