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Part1:IdentificationofMicroscopicPlankton
Organism Size Morphology MicroscopeIdentification
Virus 0.01to0.3µm
Viruseshaveacapsid,orproteincoatthatholdstheirDNA.Thiscapsidisoftenicosahedral(20equilateraltrianglesidesarrangedroughlyspherically).VirusesvarymorphologicallyaroundabasicbodyplaninvolvingthecapsidandsomestructuresforinjectingDNAorRNAintotheirhost.Somehavearelativelylongcontractiletailwithmanyfibersanddockingstructures(e.g.T-4phage).Othershaveshort,thick,fixedtails(e.g.podophages).Viruseshavelittleinternalmorphology.Theydonothaveanucleusororganelles.Theydonothavechlorophyll.Insideavirusthereisonlynucleicacid(DNAorRNA).
Cannotbeseenunderalightmicroscope,butdoappearassmallspecksunderUVepi-fluorescence.CanbeseenwithElectronMicroscopy.
Prokaryote 0.3to10.0µm
Fourmajorcelltypes:spherical,rod-shaped,spiralorcomma-shaped.Prokaryoteshaveanoutermembrane.Somehaveflagella,whicharetail-likeprojections,usedformotility.Forexample,Vibriobacteriaarecomma-shapedwithsingleflagellaatoneendwhileSynechococcusbacterialackanyflagella.Prokaryotesdonothaveanucleusormembrane-boundorganelles.Theyhaveacellularmembraneandsomeorganizedinternalstructure.Maycontainchlorophyll(e.g.cyanobacterialikeProchlorococcus)
Canbeseenunderalightmicroscope.Theyappearasspheres,commas,rods,orspirals.UnderUVlight,therewillnotbeaconcentrationofcolorinonearebecausethereisnonucleusinthesecells.
Eukaryote 2to200µm
Single-celledEukaryoteshaveawidediversityofexternalmorphology.Theycanhavecomplexshapes,modifiedformotility.Theymayalsohavebodiesmadeoutofcalciumcarbonate(ex.coccolithophores)orsilicaplates(ex.diatoms)orcellulosearmor(ex.dinoflagellates).Dinoflagellateshave2flagellaandsomehavearmorthatformselaborateshapeslike“horns”(e.g.Ceratium).Internally,eukaryoteshaveanorganizednucleusandmembrane-boundorganelles.Theycancontainchloroplasts(e.g.Coccolithophore)allowingthemtophotosynthesize.
Comparedwithvirusesandprokaryotes,eukaryotescanbeseenmuchmoreclearlyinmicroscopesbecausetheyaremuchlarger.UnderUVlight,thenucleuscanbeseenasaconcentrationofblueorgreenlightatthecenterofthecell.
EpifluorescenceMicroscope:BlueLight
Whenexcitedbybluelight,chlorophyllpigmentsinphytoplanktonnaturallyemitredlight.Organismsthathavechlorophyll,andthereforecanphotosynthesize,willbevisibleinthislight.
LightMicroscope
Lightmicroscopesusevisiblelightandaseriesoflensestoseemicroorganisms.Thistypeofmicroscopecanmagnifyupto1000timesthesizeoftheorganismwitharesolutionof0.2um.Stainscanbeusedtohelpvisualizeorganisms
EpifluorescenceMicroscope:UVlight
Fluorescenceoccurswhenmatterabsorbslightandthenemitslightatalongerwavelength.Microscopesthatopticallyseparatethesecolorsareusefulforidentifyingphytoplankton.CellsdyedwithDNAstainwillbeblueorgreenwhenexposedtoUVlight.
ElectronMicroscopeMicroscopethatusesaparticlebeamofelectronstoilluminatethespecimenandproduceamagnifiedimage.
Electronmicroscopeshaveagreaterresolvingpowerthanalight-poweredopticalmicroscopeandcanachievebetterthan0.0002umresolutionandmagnificationsofupto2,000,000x.
Organism1
LightMicroscope
Bar=5um
EpifluorescenceMicroscope:BlueLight
EpifluorescenceMicroscope:UVlight ElectronMicroscope
Organism2
LightMicroscope EpifluorescenceMicroscope:BlueLight
EpifluorescenceMicroscope:UVlight ElectronMicroscope
LightMicroscopeOrganism3
EpifluorescenceMicroscope:UV ElectronMicroscope
EpifluorescenceMicroscope:BlueLight
Organism4
LightMicroscope EpifluorescenceMicroscope:BlueLight
EpifluorescenceMicroscope:UVlight ElectronMicroscope
Organism5
LightMicroscope EpifluorescenceMicroscope:BlueLight
EpifluorescenceMicroscope:UVlight ElectronMicroscope
Bar=.05um
Organism6
LightMicroscope EpifluorescenceMicroscope:BlueLight
EpifluorescenceMicroscope:UVlight ElectronMicroscope