experiments with algae student handouts

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?