Introduction to Plants

* Introduction to the Plant Kingdomcopyright cmassengale

copyright cmassengale

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*Early AncestorsAquatic to Terrestrial Lifecopyright cmassengale


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*Aquatic AncestorClosest living species to a possible land plant ancestorGroup of green algaeCalled Charyophyceans

Characopyright cmassengale


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*Algae & Land Plant SimilaritiesBoth contain chlorophylls a and bHave chloroplasts with stacks of thylakoidsStore starch in plastidsCellulose in cell wallsGo through Alternation of Generations life Cycle



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*Terrestrial HabitatAquatic Habitatcopyright cmassengale


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*Living in Aquatic EnvironmentsPlants surrounded by water so dont dry outSperm swims to eggWater supports plantPlants stay in upper surface near lightAbsorb nutrients from the H2O



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*Plant Adaptations to LandProblems:Need mineralsGravityIncrease in Height for LightAdaptations for Drier environmentReproduction

Solutions:Roots absorb H2O & mineralsLignin & cellulose in cell wallsVascular Transport SystemWaxy cuticle & stomata with guard cellsPollen containing sperm



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*How Are Plants All Alike?copyright cmassengale


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*Plant CharacteristicsMulticellularAutotrophic (photosynthesis)Chlorophylls a and b in thylakoid membranesSurrounded by cell walls containing cellulose (polysaccharide)Store reserve food as amylose (starch)



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*Plant ReproductionAlternation of generations life cycleDiploid (2n) sporophyte stageHaploid (1n) gametophyte stageProduce multicellular embryo protected inside multicellular haploid (gametophyte egg sac) tissue



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*Plant ReproductionDiploid (2n) sporophyte stage produces haploid spores by meiosisHaploid spores undergo mitosis to produce gametophyte stageGametophyte makes gametes (eggs and sperm) by meiosisZygote (2n) produces the new sporophyte



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*Alternation of Generations2n Sporophyte2n gametophyte1n pollenOvary with 1n ovules (eggs)2n seed with plant embryoSporophyteGametophytecopyright cmassengale


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* Plant Divisionscopyright cmassengale


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*TaxonomyPlants are divided into two groupsBased on the presence or absence of an internal transport system for water and dissolved materialsCalled Vascular System

Vascular Bundlescopyright cmassengale


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*Vascular SystemXylem tissue carries water and minerals upward from the rootsPhloem tissue carries sugars made by photosynthesis from the leaves to where they will be stored or usedSap is the fluid carried inside the xylem or phloem



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*Nonvascular PlantsDo not have vascular tissue for support or conduction of materialsCalled BryophytesRequire a constantly moist environment

Moss Gametophytes & SporophytesSporophyte stageGametophyte Stagecopyright cmassengale


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*Nonvascular PlantsPlants cant grow as tallCells must be in direct contact with moistureMaterials move by diffusion cell-to-cellSperm must swim to egg through water droplets



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*Nonvascular PlantsIncludes mosses (Bryophyta), liverworts (Hepatophyta), and hornworts (Antherophyta)

LiverwortsHornwortscopyright cmassengale


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*Main Parts of Vascular PlantsShoots

-Found above ground-Have leaves attached- Photosynthetic part of plantRoots

-Found below ground-Absorb water & minerals-Anchor the plantcopyright cmassengale


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*Vascular PlantsAlso called TracheophytesSubdivided into two groups -- Seedless vascular plants and Seed-bearing vascular plants

Club Mosscopyright cmassengale


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*Seedless Vascular PlantsIncludes club moss (Lycophyta), horsetails (Sphenophyta), whisk ferns (Psilophyta), and ferns (Pterophyta)

HorsetailsWhisk fernscopyright cmassengale


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*Seed-Producing Vascular PlantsIncludes two groups Gymnosperms and AngiospermsGymnosperms have naked seeds in conesAngiosperms have flowers that produce seeds to attract pollinators and produce seeds



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*GymnospermsConiferophyta are known as conifersIncludes pine, cedar, spruce, and firCycadophyta cycadsGinkgophyta - ginkgo

GinkgoCycadcopyright cmassengale


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*GymnospermsContains the oldest living plant Bristle cone pineContains the tallest living plant Sequoia or redwood



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*AngiospermsFlowering plantsSeeds are formed when an egg or ovule is fertilized by pollen in the ovaryOvary is within a flowerFlower contains the male (stamen) and/or female (ovaries) parts of the plant Fruits are frequently produced from these ripened ovaries (help disperse seeds)



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*AngiospermsDivision AnthophytaSubdivided into two groups Monocots and DicotsMonocots have a single seed cotyledonDicots have two seed cotyledons



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*MonocotsParallel venation in leavesFlower parts in multiples of 3Vascular tissue scattered in cross section of stem



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*DicotsNet venation in leavesFlower parts in multiples of 4 or 5Vascular tissue in rings in cross section of stem



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*Plant Usescopyright cmassengale


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*Why We Cant do Without Plants!Produce oxygen for the atmosphereProduce lumber for buildingProvide homes and food for many organismsPrevent erosionUsed for food



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*More Reasons We Cant do Without Plants!Produce wood pulp for paper productsSource of many medicinesOrnamental and shade for yardsFibers such as cotton for fabricDyes



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Introduction to Plants

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Transcript of Introduction to Plants