Algaculture & Biofuels: Experiments With Algae Objective: 1. Students will be able to identify the resources algae need to survive and grow. o Students will be able to describe how algae responds to light o Students will be able to describe how algae respond to a nitrogen source o Students will be able to describe how algae respond to presence of CO2 o Students will be able to describe how algae respond to heat Description: In this activity, you will conduct one or more experiments to learn about how algae survive and grow. You will take on the role of a scientist whose job is to determine the resources needed to successfully raise algae for biofuel production. You will need to determine how algae responds to light, heat, CO2, or nitrogen fertilizer in order to determine what resources will be needed for a successful algaculture system. Each experiment will be accompanied by a list of materials, a procedure, and a series of questions you will need to answer. In conducting each experiment, you will use the scientific method. The steps of the scientific method are: 1. Question: What question are you trying to answer? 2. Research: What information already exists that may answer the question? How trustworthy is this information? What information is missing? 3. Hypothesis: What answer do you think you will come up with? Will it confirm or conflict with information you found in your research? 4. Experiment: Collect data to test your hypothesis. What kind of data do you need? How will you get it? 5. Conclusion: Analyze the data and determine whether your hypothesis was correct, partially correct, or incorrect, and why. Did you answer the question you set out to answer? Is more data needed?
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Algaculture&Biofuels:
ExperimentsWithAlgaeObjective:
1. Studentswillbeabletoidentifytheresourcesalgaeneedtosurviveandgrow.o Studentswillbeabletodescribehowalgaerespondstolighto Studentswillbeabletodescribehowalgaerespondtoanitrogensourceo StudentswillbeabletodescribehowalgaerespondtopresenceofCO2o Studentswillbeabletodescribehowalgaerespondtoheat
Description:Inthisactivity,youwillconductoneormoreexperimentstolearnabouthowalgaesurviveandgrow.Youwilltakeontheroleofascientistwhosejobistodeterminetheresourcesneededtosuccessfullyraisealgaeforbiofuelproduction.Youwillneedtodeterminehowalgaerespondstolight,heat,CO2,ornitrogenfertilizerinordertodeterminewhatresourceswillbeneededforasuccessfulalgaculturesystem.Eachexperimentwillbeaccompaniedbyalistofmaterials,aprocedure,andaseriesofquestionsyouwillneedtoanswer.Inconductingeachexperiment,youwillusethescientificmethod.Thestepsofthescientificmethodare:
1. Question:Whatquestionareyoutryingtoanswer?2. Research:Whatinformationalreadyexiststhatmayanswerthequestion?Howtrustworthyis
thisinformation?Whatinformationismissing?3. Hypothesis:Whatanswerdoyouthinkyouwillcomeupwith?Willitconfirmorconflictwith
informationyoufoundinyourresearch?4. Experiment:Collectdatatotestyourhypothesis.Whatkindofdatadoyouneed?Howwill
yougetit?5. Conclusion:Analyzethedataanddeterminewhetheryourhypothesiswascorrect,partially
correct,orincorrect,andwhy.Didyouanswerthequestionyousetouttoanswer?Ismoredataneeded?
Algaculture&Biofuels:Exploration
ExperimentsWithAlgae-PhotosynthesisExperiment1:PhotosynthesisDescription:Inthisexperiment,you’llbeinvestigatinghowmicroalgaerespondtothepresenceofalightsource.Microalgaearetinymicroscopicplantcells,sotheyshouldbehavesimilarlytootherplants.You’llbedeterminingwhetherthisistruebytestingtwosamplesofalgaeunderdifferentlightingconditions;onewithlight,andonewithout.Ifalgaecellsrespondtolightasotherplantcellsdo,theywillusethesunlightinaprocesscalledphotosynthesis.Photosynthesisistheprocessofconvertinglightenergyfromthesunandcarbondioxidefromtheairintochemicalenergywhichisstoredinbondsbetweenatomsinorganicmoleculessuchascarbohydrates(sugars),proteins,andlipids(oils/fats).Somewasteproductsaregenerated,suchasoxygengas.Inordertodetectwhetherphotosynthesisisoccurring,wewillneedtodeterminewhetherthemicroalgaeareusingupcarbondioxideandgeneratingoxygenasawasteproduct.WewilldothisbyusingapHindicator.Whenthemicroalgaeuseupcarbondioxideandgenerateoxygen,thepHinthesolutionwillchange.ByusingapHindicator,wewillbeabletoseewhetherthepHhaschanged,andthusdeterminewhetherthecarbondioxidewasusedupandreplacedwithoxygen,whichwilltelluswhetherphotosynthesishasoccurred.Materials:
ü Algaebeadsü Plasticspoonü Smallkitchenstrainerü HydrogencarbonatepHindicatorü 2smallvialsorcuvettes,approximately5mL,withcapsü Stronglightsourceü Opaquepaperü Cleartape
Procedure:
1. Writethequestionyouaretryingtoanswerwiththisexperiment:
Question:
2. Useacomputer,mobiledevice,library,orotherresourcestoanswerthefollowingquestions:• Whatisphotosynthesis?
• Whatresourcesareusedupbyplantsinphotosynthesis?
• Whatproductsandbyproductsareproducedbyplantsinphotosynthesis?
• Domicroalgaeusephotosynthesislikeotherplants?
3. Consideringtheinformationyouuncoveredinyourresearch,writetheansweryouexpecttofindtoyouroriginalquestion.Hypothesis:
4. ExperimentalProcedure:a) Removealgaebeadsfromthetesttubebypouringthroughthekitchenstrainer.b) Usetheplasticspoontoplaceanequalnumber(approximately10)ofalgaebeadsin
twoofthethreevials/cuvettes.c) FillallthreevialstothetopwithhydrogencarbonatepHindicatorsolution.d) Capeachvialsecurely.e) Placeasmallstripoftapeoneachvial,anduseamarkerorpentowrite“SampleA”
and“SampleB”onthetwovialswithalgaebeads,and“SampleC”onthevialwithonlytheindicatorsolution.
f) IntheDataCollectionTable(below),notethatSampleAwillbeinthe“algae+light”treatmentgroupandSampleBwillbethe“nolight”treatmentgroup.SampleCwillbethe“control”group.
g) IntheDataCollectionTable(below),notethebefore-testcolorofthepHindicatorsolutionineachofthethreesamples.Usetheprovidednumberedcolorchart.
h) CutastripofopaquepaperthatisaswideastheSampleBvialistalli) WrapstripofpaperaroundtheSampleBvial,andsecureitwithtapesoitdoesn’t
falloff.j) Placebothsamples10cmfromthelightsourcek) Turnthelightsourceonl) Waitapproximately30minutesm) Turnoffthelightsourcen) RemovethepaperfromSampleB.o) IntheDataCollectionTable(below),notethecolorofthepHindicatorsolutionin
eachsample.Usetheprovidednumberedcolorchart.p) IntheDataCollectionTable,subtractthe“after”colorfromthe“before”colorto
findthecolorchange.ApositivecolorchangemeansCO2wasusedupbythealgae.q) Pourofftheindicatorsolutionthroughthekitchenstrainer,rinsethealgaebeads
withdistilledwater,placethembackinthetesttube,fillthetubewithdistilledwaterandcapit.
DataCollectionTable
Example SampleA SampleB SampleC
TreatmentGroup Nolight
Colorbeforetest(Number)
4
Colorafter30min.(Number)
5
ColorChange(Afterminusbefore)
1
FollowupQuestions:1. ForSampleA,didtheconcentrationofCO2increase,decrease,orstaythesame?
a. Howdoyouknow?
2. ForSampleB,didtheconcentrationofCO2increase,decrease,orstaythesame?
a. Howdoyouknow?
3. ForSampleC,didtheconcentrationofCO2increase,decrease,orstaythesame?
a. Howdoyouknow?
4. Basedontheseresults,canyoutellwhethermicroalgaeusephotosynthesiswhenlightispresent?
5. DidphotosynthesistakeplacewiththealgaeinSampleAthatweregivenlight?Howdoyouknow?
6. Didthisconfirmorconflictwithyourhypothesis?
7. Whatotherinformationwouldbeinterestingorusefultoknow?
Algaculture&Biofuels:
ExperimentsWithAlgae-LightIntensityandPhotosynthesisExperiment2–LightIntensityandPhotosynthesisDescription:Inthisexperiment,you’llbeinvestigatinghowmicroalgaerespondtovariationsinlightintensity.Sincemicroalgaearemicroscopicplantcells,theyusephotosynthesislikeothertypesofplantcells.Photosynthesisistheprocessofconvertinglightenergyfromthesunandcarbondioxidefromtheairintochemicalenergywhichisstoredinbondsbetweenatomsinorganicmoleculessuchascarbohydrates(sugars),proteins,andlipids(oils/fats).Somewasteproductsaregenerated,suchasoxygengas.Inordertodetectwhetherlightintensityaffectsmicroalgaephotosynthesis,wewillneedtodeterminehowmuchcarbondioxideisbeingusedupbythealgaeunderdifferentlightingintensities.WewilldothisbyusingapHindicator.Whenthemicroalgaeuseupcarbondioxideandgenerateoxygen,thepHinthesolutionwillchange.ByusingapHindicator,wewillbeabletoseehowmuchthepHhaschangedunderdifferentlightintensities,andthusdeterminehowmuchcarbondioxidehasbeenusedup.Ifmorecarbondioxideisusedupinagiventimeperiod,itwillmeanthatphotosynthesisishappeningmorequickly.Materials:
ü Algaebeadsü Plasticspoonü Smallkitchenstrainerü HydrogencarbonatepHindicatorü 6smallvialsorcuvettes,approximately5mL,withcapsü Stronglightsourceü Cleartape
Procedure:
1. Writethequestionyouaretryingtoanswerwiththisexperiment:
Question:
2. Useacomputer,mobiledevice,library,orotherresourcestoanswerthefollowingquestions:• Whatisphotosynthesis?
• Whatresourcesareusedupbyplantsinphotosynthesis?
• Whatproductsandbyproductsareproducedbyplantsinphotosynthesis?
• Willlightintensityaffecttherateofphotosynthesisinmicroalgae?
3. Consideringtheinformationyouuncoveredinyourresearch,writetheansweryouexpecttofindtoyouroriginalquestion.Hypothesis:
4. ExperimentalProcedure:a) Removealgaebeadsfromthetesttubebypouringthroughthekitchenstrainer.b) Usetheplasticspoontoplaceanequalnumber(approximately10)ofalgaebeadsin
allfivevials/cuvettes.c) Fillallfivevials(containingalgaebeads)tothetopwithhydrogencarbonatepH
indicatorsolution.d) Capeachvialsecurely.e) Placeasmallstripoftapeoneachvial,anduseamarkerorpentolabeleach
sample(SampleA–SampleE).f) IntheDataCollectionTable(below),notewhichtreatmentgroupeachsampleisin.
Atreatmentgroupwillbethedistancefromthelightsource,startingwith10cm,andtheneveryfivecmupto35cm.
g) IntheDataCollectionTable(below),notethebefore-testcolorofthepHindicatorsolutionineachofthefivesamples.Usetheprovidednumberedcolorchart.
h) Placeonesample10cmfromthelightsource,anotherat15cm,anotherat20cm,andsoonuntilallfivesamplesareplacedat5cmincrementsfromthelightsource.
i) Turnthelightsourceonj) Waitapproximately30minutesk) Turnoffthelightsourcel) IntheDataCollectionTable(below),notethecolorofthepHindicatorsolutionin
eachsample.Usetheprovidednumberedcolorchart.m) IntheDataCollectionTable,subtractthe“after”colorfromthe“before”colorto
findthecolorchange.AlargercolorchangemeansmoreCO2wasusedupbythealgae.
n) Pourofftheindicatorsolutionthroughthekitchenstrainer,rinsethealgaebeadswithdistilledwater,placethembackinthetesttube,fillthetubewithdistilledwaterandcapit.
DataCollectionTable
Example SampleA SampleB SampleC SampleD SampleE
TreatmentGroup(cmfromlightsource)
5cm
Colorbeforetest(Number) 5
Colorafter30min.(Number) 9
Colorchange(Afterminusbefore)
4
Followupquestions:
1. Usingtheblankchartbelow,plottheCO2changesasafunctionoflightintensity(distancefromthelightsource).Drawlinesconnectingthepointstoformalinegraph.
Table1.ChangeinCO2concentrationasafunctionoflightintensity
Chan
geinpHIndicatorc
olor
(decreaseinCO
2con
centratio
n)
6
5
4
3
2
1
0
10cm 15cm 20cm 25cm 30cm Distancefromlightsource
(lightintensity)
2. CanyouseeatrendbetweenlightintensityandhowmuchCO2wasused?Whattrend,ifany,doyousee?
3. Basedontheseresults,whatcanyousayabouttheeffectoflightintensityontherateofphotosynthesisinmicroalgae?Didthisconfirmyourhypothesis?Whatotherinformationmightbeusefulorinteresting?
Algaculture&Biofuels:ExperimentsWithAlgae-LightWavelengths(colors)
Experiment3–LightWavelength(Color)Description:Inthisexperiment,you’llbeinvestigatinghowmicroalgaerespondtodifferentlightwavelengths(colors).Sincemicroalgaearemicroscopicplantcells,theyusephotosynthesislikeothertypesofplantcells.Photosynthesisistheprocessofconvertinglightenergyfromthesunandcarbondioxidefromtheairintochemicalenergywhichisstoredinbondsbetweenatomsinorganicmoleculessuchascarbohydrates(sugars),proteins,andlipids(oils/fats).Somewasteproductsaregenerated,suchasoxygengas.Inordertodetectwhetherlightwavelengthaffectsmicroalgaephotosynthesis,wewillneedtodeterminehowmuchcarbondioxideisbeingusedupbythealgaeunderdifferentlightwavelengths.WewilldothisbyusingapHindicator.Whenthemicroalgaeuseupcarbondioxideandgenerateoxygen,thepHinthesolutionwillchange.ByusingapHindicator,wewillbeabletoseehowmuchthepHhaschangedunderdifferentlightwavelengths,andthusdeterminehowmuchcarbondioxidehasbeenusedup.Ifmorecarbondioxideisusedupinagiventimeperiod,itwillmeanthatphotosynthesisishappeningmorequickly.Materials:
ü Algaebeadsü Plasticspoonü Smallkitchenstrainerü HydrogencarbonatepHindicatorü 4smallvialsorcuvettes,approximately5mL,withcapsü Stronglightsourceü Cleartapeü Stripsofred,green,andbluelightfilterfilm.
Procedure:
1. Writethequestionyouaretryingtoanswerwiththisexperiment:
Question:
2. Useacomputer,mobiledevice,library,orotherresourcestoanswerthefollowingquestions:• Whatisphotosynthesis?
• Whatresourcesareusedupbyplantsinphotosynthesis?
• Whatproductsandbyproductsareproducedbyplantsinphotosynthesis?
• Willthewavelength(color)oflightaffecttherateofphotosynthesisinmicroalgae?
3. Consideringtheinformationyouuncoveredinyourresearch,writetheansweryouexpecttofindtoyouroriginalquestion.Hypothesis:
4. ExperimentalProcedure:a) Removealgaebeadsfromthetesttubebypouringthroughthekitchenstrainer.b) Usetheplasticspoontoplaceanequalnumber(approximately10)ofalgaebeadsin
allfourvials/cuvettes.c) FillallfourvialswithalgaebeadstothetopwithhydrogencarbonatepHindicator
solution.d) Capeachvialsecurely.e) Placeasmallstripoftapeoneachvial,anduseamarkerorpentolabeleach
sample(SampleA–SampleD).f) IntheDataCollectionTable(below),notewhichtreatmentgroupeachsampleisin.
Atreatmentgroupwillbethecolorofthelight:Red,Green,Blue,orControl(nocolorfilter).
g) IntheDataCollectionTable(below),notethebefore-testcolorofthepHindicatorsolutionineachofthefoursamples.Usetheprovidednumberedcolorchart.
h) Cutastripofeachcolorfiltermaterialthatisaswideasavialistall,andjustlongenoughtowraparoundavialoncewithoutoverlappingorleavingagap.
i) Wraponevialinredfilm,oneingreenfilm,andoneinbluefilm,securingeachwithasmallstripoftape.
j) Placeeachvial10centimetersfromthelightsourceandclosetotheothervials.k) Turnonthelightsource.l) Waitapproximately30minutesm) Turnoffthelightsourcen) IntheDataCollectionTable(below),notethecolorofthepHindicatorsolutionin
eachsample.Usetheprovidednumberedcolorchart.o) IntheDataCollectionTable,subtractthe“after”colorfromthe“before”colorto
findthecolorchange.AlargercolorchangemeansmoreCO2wasusedupbythealgae.
p) Pourofftheindicatorsolutionthroughthekitchenstrainer,rinsethealgaebeadswithdistilledwater,placethembackinthetesttube,fillthetubewithdistilledwaterandcapit.
DataCollectionTable
Example SampleA SampleB SampleC SampleD
TreatmentGroup(FiltercolororControl)
Red
Colorbeforetest(Number) 4
Colorafter30min.(Number) 6
Colorchange(Afterminusbefore)
2
Followupquestions:
1. Usingtheblankchartbelow,plottheCO2changesasafunctionofwavelength(color).Drawverticalcolumnstoeachpointtomakeabargraph.
Table1.ChangeinCO2concentrationbylightwavelength
Chan
geinpHIndicatorc
olor
(decreaseinCO
2con
centratio
n)
6
5
4
3
2
1
0
Red Green Blue Control(nocolor)
Wavelength(Color)
2. Canyoutellwhetherthecoloroflightaffectedtherateofphotosynthesis?Howcanyoutell?
3. Basedontheseresults,whatcanyousayabouthowmicroalgaerespondtodifferentcolorsoflight?Didthisconfirmyourhypothesis?Whatotherinformationmightbeusefulorinteresting?
Algaculture&Biofuels:
ExperimentsWithAlgae-NutritionEnrichmentExperiment4–NutrientEnrichmentDescription:Inthisexperiment,you’llbeinvestigatinghowmicroalgaegrowthratesareaffectedbythepresenceofdifferentamountsofnutrients.Microalgaearemicroscopicplantcells,andlikeotherplantcellstheyrequirevariousnutrientsinordertosurviveandgrow.Thesenutrientsareusedtostoreenergyfromthesun,buildcellstructures,andvariousotherpurposes.Theprimarynutrientsneededtosustainalgaegrowtharenitrogenandphosphorus,buttraceamountsofvariousothermineralsandmetalsarealsoneeded.Inthisactivity,you’llexperimentwithdifferentconcentrationsofacommonall-purposefertilizer(whichcontainsnitrogen,phosphorus,andmanyothernutrients)todeterminehowmuchofthesenutrientsareneededtomaximizealgaegrowth.Materials
ü Livemicroalgaeculture(chlorella,ankistrodesmus,etc.)ü All-purposewater-solublefertilizergranules(MiracleGroorequivalent)ü Severalcleancontainersorbeakersofequalsizeü Non-chlorinatedwater(springwaterfromanaturalsourceoraquariumwater)ü 6x100mLbeakersorothersimilarlysizedclearcontainersü Stronglightsourceü Cleartape
Procedure:
1. Writethequestionyouaretryingtoanswerwiththisexperiment:
Question:
2. Useacomputer,mobiledevice,library,orotherresourcestotrytoanswerthefollowingquestions:
• Whatresourcesareneededbyplantcellstopromotegrowth?
• Wheredomicroalgaegetnutrients?
• Whatconcentrationofnutrientsisrequiredtomaximizealgaegrowth?
3. Consideringtheinformationyouuncoveredinyourresearch,writetheansweryouexpecttofindtoyouroriginalquestion.Hypothesis:
4. ExperimentalProcedure:a) Usingfiveofthebeakersorothercontainers,mix100mLoffertilizer/non-
chlorinatedwatermixtureineachofthefollowingconcentrationso Regularstrength(followpackagedirections)o Doublestrengtho ½strengtho ¼strengtho 1/8strength
o Note:Thiscanbedonebymixingalargeramount(~250mL)ofdouble-strengthmixture,thenadding100mLofthistothefirstcontainer,50mLtothenextcontainer,25mLtothethirdcontainer,andsoon.Thenfilleachcontainertherestofthewayto100mLwithnon-chlorinatedwater.
b) Fillthe6thcontainerwith100mLofnon-chlorinatedwateronly(nofertilizer)c) Usingthecleartapeandamarker,labeleachcontainerwithasampleletter(A-F)
andthefertilizerconcentration(Double,regular,half,etc.).Labelthewater-onlysampleas“Control.”
d) Add5mLoflivealgaeculturetoeachofthecontainer,includingthewater-onlybeaker.
e) Capeachvialsecurely.f) IntheDataCollectionTable(below),notewhichtreatmentgroupeachsampleisin.
Atreatmentgroupwillbethefertilizerconcentration,orControl(nocolorfertilizer).g) IntheDataCollectionTable(below),notethebefore-testcolorofthe
algae/fertilizer/watermixtureineachofthesamples.Usetheprovidednumberedcolorchart.
h) Looselycovereachcontainerwithplasticwrapsothataircangetinandout,butsothatdustandothercontaminantsarekepttoaminimum.
i) Placeeachcontainer30centimetersfromthelightsourceandclosetotheothercontainers.
j) Turnonthelightsource.k) Allowseveraldaysforalgaegrowthtotakeplacel) Turnoffthelightsourcem) IntheDataCollectionTable(below),notethecolorofthealgae/fertilizer/water
mixtureineachsample.Usetheprovidednumberedcolorchart.n) IntheDataCollectionTable,subtractthe“after”colorfromthe“before”colorto
findthecolorchange.Alargercolorchangemeansmorealgaegrowthtookplace.o) Discardthealgaemixtureandcleananddrythecontainersandallothermaterials
DataCollectionTable
Example SampleA SampleB SampleC SampleD SampleE
TreatmentGroup(Fertilizerconcentration
orControl)0.125X
ColorbeforeTest(Number)
2
ColorafterTest(Number)
12
Colorchange(Afterminusbefore)
10
Followupquestions:
1. Usingtheblankchartbelow,plottheCO2changesasafunctionoffertilizerconcentration(color).Drawlinestoconnecteachpointtoformalinegraph.
Table1.
Algaegrowthasafunctionoffertilizerconcentration
Chan
geinalgaecolor
6
5
4
3
2
1
0
2X 1X 0.5X 0.25X 0.125X Control(0X)
Fertilizerconcentration
2. Canyoutellwhethertheconcentrationoffertilizeraffectedalgaegrowth?Howcanyoutell?
3. Basedontheseresults,wasyourhypothesisconfirmed,notconfirmed,ordoyouneedmoreinformation?Whatotherinformationmightbeusefulorinteresting?
4. Isthereanidealconcentrationoffertilizer(onethatproducesthemostalgaegrowth)?Ifso,whatisit,andhowdoyouknow?
Algaculture&Biofuels:
ExperimentsWithAlgae-PlantGrowthandCarbonDioxide
Experiment5–CarbonDioxideAvailabilityDescription:Inthisexperiment,you’llbeinvestigatinghowmicroalgaegrowthratesareaffectedbytheavailabilityofcarbondioxide.Microalgaearemicroscopicplantcells,andlikeotherplantcellstheyrequirecarbondioxideforphotosynthesis.Photosynthesisusescarbondioxidefromtheatmosphere,water,andenergyfromthesuntocreatesugarmoleculeswhereenergyisstored,andoxygengasasawasteproduct.Carbondioxidemakesuponlyabout0.04percentoftheairwebreathe,butthisismorethanenoughtosupportallthephotosynthesistakingplaceinalltheplantlifeonearth!Inthisactivity,you’llexperimentsupplyingalgaewithdifferentamountsofairtofindouthowalgaerespondtoincreasedordecreasedlevelsofcarbondioxide.Materials
ü Livemicroalgaeculture(chlorella,ankistrodesmus,etc.)ü Non-chlorinatedwater(springwaterfromanaturalsourceoraquariumwater)ü 3smallsodabottles(20oz.orless)ü All-purposewatersolublefertilizergranules(MiracleGroorequivalent)ü 1aquariumairpump/airstone(smallenoughtofitinsideyourcontainer)ü 1electricdrillandasmallsetofbitsü Stronglightsourceü Cleartape
Procedure:
1. Writethequestionyouaretryingtoanswerwiththisexperiment:
Question:
2. Useacomputer,mobiledevice,library,orotherresourcestotrytoanswerthefollowingquestions:
o Whatresourcesareneededbyplantcellstopromotegrowth?
o Wheredomicroalgaeacquirecarbondioxideneededforphotosynthesis?o Whatbyproductsareproducedfromphotosynthesis?
3. Consideringtheinformationyouuncoveredinyourresearch,writetheansweryouexpecttofindtoyouroriginalquestion.Hypothesis:
4. ExperimentalProcedure:a. Filleachbottleabout¾fullofnon-chlorinatedwater.b. Addanequalamountoffertilizergranules(asmallpinch,about1/8teaspoon)to
eachbottle,thenclosethebottlestightlyandswirluntilthefertilizerhascompletelydissolvedinthewater.
c. Usingthecleartapeandamarker,labeleachcontainerwithasampleletter(A-C).d. Removethecapsontwoofthebottles,anddrillthefollowingholesinthetwo
caps:o Bottle1:Drilltwoholesofequalsizethatarejustlargeenoughto
snuglyfittheplastictubefromyourairpumpthroughthecap.o Bottle2:Inthetopofthesecondcap,drill6-8smallerholes
e. Add5mLoflivealgaeculturetoeachbottle.f. Prepareeachbottleasinstructedbelow:
o Bottle1(twolargeholesinthecap):Threadtheplastictubefromyourairpumpthroughthecapanddownintothewatersothattheendnearlytouchesthebottom.Youmayneedtoweightheendofthetubeoruseasmallairstone.Thesecondholewillallowairtoescapeasmoreairispumpedin.Onceyouhavetheairtubeinstalled,capthebottlesecurelywiththeairtubeinplace,thenturnonthepump.Ifwaterspillsoutwhenthepumpison,youmayneedtopourasmallamountofwateroutuntilthewaterdoesn’tsplashout.
o Bottle2(withseveralsmallerholesdrilledinthecap):Closeitsecurelyusingthecapwithseveralsmallholes.
o Bottle3(withnoholesinthecap):Capthebottlesecurelysothatnoaircangetinorout.
5. IntheDataCollectionTable(below),notewhichtreatmentgroupeachsampleisin.Thereare3treatmentgroupsrepresenting3levelsofCO2availability:Pumpedair,Passive(airholes,nopump),andControl(sealedbottle,nooutsideairexchange).
6. IntheDataCollectionTable(below),notethebefore-testcolorofthealgae/fertilizer/watermixtureineachofthesamples.Usetheprovidednumberedcolorchart.
7. Placeeachcontainer30centimetersfromthelightsourceandclosetotheothercontainers.8. Turnonthelightsource.9. Allowseveraldaysforalgaegrowthtotakeplace.10. Turnoffthelightsource.
11. IntheDataCollectionTable(below),notethecolorofthealgae/fertilizer/watermixtureineachsample.Usetheprovidednumberedcolorchart.
12. IntheDataCollectionTable,subtractthe“after”colorfromthe“before”colortofindthecolorchange.Alargercolorchangemeansmorealgaegrowthtookplace.
13. Discardthealgaemixtureandcleananddrythecontainersandallothermaterials
DataCollectionTable
Example SampleA SampleB SampleC
TreatmentGroup(Forced,Passive,or
Control)Passive
ColorbeforeTest(Number)
2
ColorafterTest(Number)
5
Colorchange(Afterminusbefore)
3
FollowupQuestions:
1. Usingtheblankchartbelow,plottheCO2changesasafunctionoffertilizerconcentration(color).Drawverticalcolumnstoeachpointtoformabargraph.
Table1. AlgaegrowthasafunctionofCO2availability
Chan
geinalgaecolor
6
5
4
3
2
1
0
Pump(mostCO2)
PassiveExchange(lessCO2)
Control(NooutsideCO2)
CO2Availability
2. CanyoutellwhethertheavailabilityofCO2affectedalgaegrowth?Howcanyoutell?
3. Basedontheseresults,wasyourhypothesisconfirmed,notconfirmed,ordoyouneedmoreinformation?Whatotherinformationmightbeusefulorinteresting?
4. WhichlevelofCO2availabilityproducedthemostalgaegrowth?Whydoyouthinkyougotthisresult?
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