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Team Number: ____________ Team Name: ______________________________ Participant Names: ______________________________ ______________________________

2016-2017 Ecology Exam

February 4, 2017

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1. Rhizobiaarebacteriathatliveintherootnodulesofleguminousplantsandcanfixatmosphericnitrogeninnitrogenouscompounds.Theplantscanusethesecompoundsintheirmetabolism,whilethebacteriauseglucoseproducedbytheplants.WhatisthetermthatbestdescribestherelationshipbetweenRhizobiumandtheplant?[2]

A. ParasiticB. MutualisticC. Competitive

2. FishAisalargefishthatfeedsprimarilyonFishBandFishC.FishBlivesonphototrophic

plankton.FishClivesonzooplankton(whichconsumephototrophicplankton)andonFishD,whichisanherbivore.

i. Drawthefoodwebforthissituation.[5]

ii. WhichlabelscanbeascribedtoFishAinthissituation?[2]

A. ProducerandconsumerB. PrimaryandsecondaryconsumerC. Secondary,tertiary,andquaternaryconsumerD. Secondaryandtertiaryconsumer

3. Acanalhadalargepopulationofvariouskindsoffish.Afterfarmersintheareastartedusingnitrogenousfertilizersontheirfields,rainwaterwashedexcessfertilizerintothecanal.Afterafewdays,thenumberofalgaeinthepondincreasedgreatly,whilethelocalfishpopulationdecreaseddramatically.

i. Whatisthetermfortheprocessdescribedabovewherebyanincreaseinthe

availabilityofnutrientsresultedinanincreaseinalgae?[1]

ii. Whymightthefishpopulationhavedecreased?NamethemainTWOfactorsthatcouldhavethisledtothisdecreaseandexplaintheeffectthesefactorswouldhaveonthefishpopulation.[3]

iii. Thepresenceofalgaeisabioticfactorinfluencingthefishpopulation.Name

ONEmorebioticandTWOabioticfactorsthatcaninfluencethefishpopulation.[3]

4. Aplantisgrowinginamarshyarea.Theplantcannotgrowondrylandbecauseitneedsa

greatdealofwatertosurvive.However,itcannotgrowindeepwater.SuggestTWOmainreasonswhytheplantmaybeabletogrowonlyinshallowwater.[4]

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Questions5-9dealwiththefollowinghypotheticalecologicalscenario:Apopulationofdeerissuddenlyseparatedwhenahighwayisbuiltthatsplitsthepopulation’shabitatintwo.Thetwogroupscannolongerreproducewithoneanother.Visioninthesedeerisdeterminedbyallelesinasinglegene,withQbeingthedominantallele.Poorvisioninthesedeerisduetohomozygosityfortherecessivealleleq.

5. Whatkindofreproductivebarrierisrepresentedinthisscenario?[2]

A. GeographicisolationB. TemporalisolationC. Behavioralisolation

6. Mostdeerkeeptotheirnewhabitats;however,someindividualswithpoorvisionattempt

tocrossthehighway.Mostofthesedeerdieduetooncomingtraffic.Whatevolutionaryprocessdoesthisdemonstrate?Whatspecifictypeofthisprocessistakingplace?[4]

7. IftheprevalenceofalleleQinthetotalpopulationis63%andthepopulationisinHardy-

Weinbergequilibrium,whatpercentageofthepopulationpossessesthegenotypeQq?Whatisthephenotypefordeerwiththisgenotype?[3]

8. Duetothedeathsofmanydeerwiththegenotypeqq,theprevalenceofalleleQinthe

populationincreases.Iftheprevalenceofalleleqis77%ofwhatitwasoriginally(inthesituationdescribedinquestion5c),whatpercentageofdeernowhavegoodeyesight?(AssumethattheonlyfactorinfluencingeyesightistheQgeneandthatthispopulationisinHardy-Weinbergequilibrium.)[3]

9. Aftermanyyears,thehighwayisabandonedandthetwopopulationsarereunited.

However,individualsarenowunabletobreedacrossthedifferentpopulations.Theycanonlybreedwithindividualsfromtheirowngroup.Whatprocesshastakenplace?[2]

A. SpeciationB. ArtificialselectionC. GeographicreproductivebarrierD. Alienation

10.Certainfishspecieshavebecomeendangeredduetooverfishing.Ithasbeenmadeillegaltofishforsomeofthesespecies.Still,theirpopulationscontinuetodecline.Suggesttwopossiblereasonsthatthefishingindustryisstillcausingadeclineinthepopulationsofthesefishspecies,eveniftheyarenotbeingfishedfor.(Writeonesentenceforeachreason.)[4]

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11.Thischartshowstherelativepopulationnumbersofthreespeciesofbacteriaintwodifferentcolonies.OnlytypesBandCwereintroducedtocolonyX,withaninitialratioof1:1(theinitialrelativepopulationswere50forbothspecies).AllthreebacterialspecieswereintroducedtoColonyYina1:1:1ratio(i.e.initialrelativepopulationswere33forallspecies).Population BacteriumA BacteriumB BacteriumC

X 0 49 51

Y 97 2 1Basedontheabovedata,whattypeofinteractionistakingplacebetweenbacterialspeciesA,B,andC?Twoanswersarecorrect.[4]

A. BandCarebothpredatorstowardsAB. BandCarebothcompetitorsofAC. AisapredatorofbothBandCD. BandChaveamutualisticrelationshipE. AandBhaveamutualisticrelationshipandarepredatorsofCF. BandCcompetewitheachother

TiebreakerQuestion12.Suggestasmanyobservationsasyoucanthatyouwouldseeinanareawhereecological

successionistakingplace.[5]TiebreakerQuestion13.Namethetwobiogeochemicalcyclesshown.Foreachofthesecycles,statetheglobal

humanactivitythatmostimpactsitandhowtheactivitycontributestoclimatechange.[6]

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Questions14-19dealwiththefollowingbiomemapbelow:14.Whattypesofleafshapesareoftenfoundontreesinthebiomethatiscoloredblue?[2]

A. ObovateB. Lance-shapedC. Needleleaf,conical

15.Inthebiomethatiscoloreddarkpurplenearthetop,whatistheprimarychallengefacedbyvegetationthatlimitsthemaximumheighttowhichtheycangrow?[2]

A. LackofsunlightforabouthalftheyearB. LowfertilesoilcontentduetopermafrostC. Thicklayersofsnowcoverinwinter

16.Namethreephysicaladaptationsthatmammalsintheblue-coloredbiomeusuallypossessforsurvivalinthewinterseason.[3]17.Animalsinthepurple-coloredbiomeoftenexhibittwobehavioraladaptationsthathelpthemsurvivewinterconditionsintheirenvironment.Namethesetwobehaviors.[2]18.Thebiomeshowninbrightredisatypeofforestthatisuniquefromotherforestbiomesduetooneadaptationsharedbyitstrees.Namethatoneadaptation.[1]19.Howdoesthisoneadaptation,sharedbymostplantsinthebiomeshowninred,contributetothehighspeciesrichnessofthebiome?[2]

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20.Duetotheextremeconditionsoflowtemperatureandprecipitationintaigaecosystems,thesoilcantakeonuniqueproperties,formingaspecialorganicsubstancethatisfoundallaroundthetaiga.Whatisthisspecialmattercalled?[2]

A. PermafrostB. GreenmanureC. MuskegD. Compost

21.Whichofthechoicesliststwoadaptationsthatallowvegetationinborealforeststoendure

theharshclimateofthetaigaecosystem?[2]A. Perennialplantgrowth;seasonalleafchangesB. Darkcolorofleaves;yearlongretentionoffoliageC. C4photosynthesispathway;bushygrowthclosetothegroundD. Antifreezeproteins;large,thinleavesforsunlightabsorption

22.Certainplantspeciesinthetaigabiomelikethedominantwhitespruceandbalsamfironly

appearintheecosystemmanyyearsafteramajordisturbanceintheenvironmentoccurs,suchasnaturaldisasters.Manyofthesespeciesarealsonotresistanttodisturbances,beingamongthelasttocolonizeahabitat.

i. Whatisthetermforthetypeofsuccessionalcommunitythatmanyoftheseplants

wouldbelongto,whichoccursatthepeakperiodforanecologicalcommunity?[2]A. ClimaxcommunityB. SeralcommunityC. PrimarycommunityD. Secondarycommunity

ii. Wouldthisecologicalstatebeachievedthroughprimarysuccessionorsecondary

succession,orboth?[2]

iii. Certaindisturbanceforcesareimportantformaintainingthediversityofspeciesinanecosystem.Whichnaturalforceisparticularlyusefulforplantthinning?[1]

23.Thetundraisknownforbeingaharshbiomewithlittlevegetativematterandnotableforthelackoftreesduetoitsharshenvironmentalextremes.Whichofthefollowingisatraitthatisexclusivelydistinguishingofthetundra?[2]

A. VegetationthatonlygrowsclosetothegroundB. LowtemperaturesandprecipitationduetocoldairandhighlatitudesC. UnevendistributionofsunlightthatdeprivesplantsofenergyD. Shortsummersandlongwinters

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24.Afisheriesbiologistwishestooptimizeheryieldbymaintainingapopulationoftroutatexactly1000individuals.Predicttheinitialinstantaneousgrowthrateifthepopulationisstockedwithanadditional700fish.Assumeris0.008individuals/(individual*day).[2]

A. -2.04individualsperdayB. 3.72individualsperdayC. 2.04individualsperdayD. -1.28individualsperday

25.Supposethatapopulationofalligatorsisgrowingaccordingtothelogisticcurveequation.If

thecarryingcapacityis260alligatorsandr=0.05individuals/(individual*month),whatisthemaximumpossiblegrowthrateforthisspecificpopulation?[2]

A. 3.25individualspermonthB. 3.01individualspermonthC. 1.04individualspermonthD. 1.76individualspermonth

Questions26-28refertothegroupofsurvivorshipcurvesbelow:

AnswereachquestionwithTypeI,TypeII,orTypeIIIastheanswer.[2pointsperquestion]26.Whichofthesurvivorshipcurvesinthegraphistypicallyobservedinsomelizardspecies?27.Characteristicofspeciesthatexhibitr-selectionstrategyinproductionofoffspring28.Typicalforrelativelylargespeciesthatproducefewoffspringbutcareforthemwellinintimateparentalrelationships

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29.Asaratherunforgivinglocationforlifetodevelop,thetundrahasforcedthefewplantsthatcansurviveitsharshconditionstotakeonvariousadaptations.

i. Whichofthefollowingisaproperadaptationthatcontributestoaplant’syearlong

survivalinthetundrabiome?[2]A. ConicalleafshapesB. ShadetolerancetocopewithlowlightlevelsC. BrightlycoloredfoliagewithseasonalvariationsD. Perennialplantgrowth

ii. Manynativetypesoftundravegetationarechamaephytes,whichmeansthatthey

__________tothegroundinordertoavoidhigh________.[4]

30.Whatdoestheterm“deciduous”mean,andhowdoesitrelatetodescribingtheoverall

climatepatternsofthedeciduousforestbiome?[2]A. Tofallofforshed;suggestsmildseasonalweatherpatternsleadingtopredictable

changesinbothtemperatureandprecipitationB. Referstoplantsthatloseleavesseasonally;suggeststwolongseasons:wetanddryC. Dominatedbygrasses;suggestsmildclimatepatternsthatoccurincyclesD. Possessesbudsthathibernateinwinter;suggestshighprecipitationatconstant

levelsthroughtheseasonsandretentionoffoliageyear-round31.Inatypicaldeciduousforestbiome,howmanydistinctseasonsareobservedthroughout

thecourseofatypicalyear?[2]A. TwoseasonsB. FourseasonsC. OneseasonD. Threeseasons

32.Deciduousforestshaveamoreabundantassemblageoflifeintheirecosystemsranging

frommanyspeciesofforestwildlifelikedeer,raccoons,andbirdstomanykindsofplantsfromshrubsandundergrowthtohardwoodtrees.Fromthefollowingfactors,choosetheTWOthatareMOSTresponsibleforthisdiversityofspeciesandtheirdistribution.[4]

A. LowtemperaturesbelowfreezingB. SuccessivechangingoftheseasonsonadefinedcycleC. ModerateamountsofprecipitationthroughouttheyearD. AvailabilityofabundantfoodfromstandingtreesE. Seasonalappearanceanddisappearanceoftheforestcanopy

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33.Biodiversityoflandspecies,especiallyinthetropics,hasbeenthreatenedforyearsbyhumanactivitiesofdeforestationandindustrializedagriculture.Despiteeffortstocutbackonsuchdestructiveactivities,manyspeciesremainthreatened.Whataretwootherareasofhumanimpactthatmaycontributetothecontinueddeclineofglobalbiodiversity?[2]

A. Overgrazingbylivestock;globalcoolingthroughvolcanoesB. Emissionofgreenhousegases;replantingtreesinnewgrowthforestsC. Introductionofinvasivespecies;useofchemicalfertilizersandpesticidesD. Recyclingofusedmaterials;recreationalhuntingofendangeredspecies

34.Windsinthetundraoftenreachspeedsofupto______mph.[2]

A. 10-20B. 50-80C. 10-30D. 30-60E. Noneoftheabove

35.Lossofprotectivevegetationposesseriousrisksforthehealthoftheecosystemsthatthey

wereformerlylocatedin,suchassoilerosion,aprocessthatcanleadtothedeteriorationofsoilqualityinanenvironmentanditsecologicalwell-beingoveryears.

i. Whataretwofactorsthatexplainhowvegetationcoveroccupiesanimportantrole

inpreventingexcessivesoilerosion?ChoosethebestTWO.[4]A. SlowingdownofsurfacerunofffromrainstormsB. AttractivenesstolargeanimalsforshelterC. HighcompetitionamongspeciesforsunlightD. RootsholdingdownsoiltopreventitfromwashingawayE. Storageofsugarsandstarchesintubers

ii. Whichofthefollowingmajorhumanactivitiesdisruptsthehealthofvulnerable

naturalenvironmentsthroughthestrippingofvegetation?[2]A. ConstructionofdamsalongmajorriversB. StripminingforpreciousmetalsandmineralsC. Deforestationthroughslash-and-burnagricultureD. Emissionofgreenhousegassesfromburningoffossilfuels

36.Inspiteofthegrowingriskofsoilerosioninhabitatsandenvironmentsaroundtheworldwithincreasinghumanactivity,thereareconcretemethodsthathavebeendevelopedinrecentyearstocombatsoilerosionandminimizeitsdamage.NameTWOsuchpractices.[4]

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Questions37-43refertothefollowingexponentialandlogisticgrowthcurvesbelow.Answereachquestionwiththeletterreferringtothepartofthegraphthatbestfitseachdescription.[2pointsperquestion]37.Phasewheretheinstantaneousgrowthforapopulationthatfollowsapatternoflogistic

growthreachesitsmaximumvalue38.Pointwherepopulationsthataresubjecttodensity-dependentgrowthfactorsreachthe

limitsatwhichtheirenvironmentscanadequatelysupportallindividuals39.Stageatwhichtherateofgrowthbeginstodecreaseinmagnitudeasthefiniteamountof

resourcesofanecosystemareexhaustedbyagrowingpopulation40.Initialstageduringwhichpopulationsstarttoexpandfromafewselectindividualsasthey

taketimetodeveloppriortoreproduction41.Pointatwhichintraspecificcompetitionoccurs,leadingtonaturalselectionasindividuals

whohavedifferentadaptationstotheirenvironmentcompetewitheachotherforsurvival42.Constantlyexpandinggrowthratethatischaracteristicofanexponentialgrowthpattern

startsfromthisphasewithfewindividualsgrowingslowlydespiteabundanceofresources43.Divergencesbetweenexponentialandlogisticgrowthcurvesbecomeprominentfromthis

phase,allowingthedevelopmentofcharacteristicS-shapecurve

B

A

C

D

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44.Theprimarystagesofthenitrogencycleare(startingwithatmosphericN2):[2]A.ammonification,denitrification,nitrogenfixation,nitrification,assimilationB. nitrogenfixation,ammonification,assimilation,nitrification,phosphorylationC. respiration,decarboxylation,quantification,nitrification,assimilationD. nitrogenfixation,nitrification,assimilation,respiration,ammonificationE. nitrogenfixation,nitrification,assimilation,ammonification,denitrification

45.Septicwatersystemsareoftencontaminatedwithbacteriafromanimalwaste.Suppose

thatawatertankisinfestedwithacolonyof80,000E.colibacteria.Ifthenumberofbacteriapresentinthetankafter10daysis190,000,determinethedoublingtime.[2]

46.Whichofthefollowingbestdescribesarelationshipinwhichtwospeciesbothmutually

benefitfromeachother’sbehaviors?[2]A. SymbiosisB. CompetitionC. ParasitismD. CommensalismE. Mutualism

47.Whenresourcesareabundantandtheenvironmentisstable,whichreproductivestrategy

wouldbemosteffectiveforspeciessurvival?[2]A. AsexualreproductionthroughbuddingB. Sexualreproduction,withminimalparentalcareandrapiddevelopmenttomaturityC. Sexualreproduction,withintimateparentalcareandslowdevelopmenttomaturityD. AlloftheaboveE. Noneoftheabove

48.AhealthypopulationofDouglasfir,aperennialevergreentree,increasesby13%peryear.

Calculatethedoublingtimeforthispopulation.Includeunits.[2]49. Abouthowmuchenergyislostbetweeneachsuccessivetrophiclevelofatypicalenergy

pyramidforadevelopedecosystem?[2]A. 10%B. 50%C. 90%D. 99%E. noneoftheabove

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50.Thetotalamountofenergycontainedatthefirsttrophiclevelthatisavailabletothefirst

levelofconsumersinanyecosystemiscalled:[2]A. energytransferB. netprimaryproductionC. grossprimaryproductionD. carbonfixationE. energyinput

51. Changesintheseasonsthroughouttheyearareprimarilycausedby:[2]

A. periodicbuildupofheatenergyattheequator.B. anannualcycleofvariationsinthesun’stotalenergyoutput.C. thetiltoftheEarth'saxistowardorawayfromthesun.D. variationsincyclesoftemperaturechangeandrainfall.E. changesinthedistancebetweenEarthandthesun.

52.Aresearcheronpopulationdynamicsofmonarchbutterfliesestimatesthatthesizeofone

populationis7,000.Overamonth,yourecord980birthsand120deathsinthatpopulation.Estimaterandcalculatewhatthepopulationsizeispredictedtobein9months.[5]

53.Whatistheprimaryreasonthatfrequentforestfiresarebeneficialforthetaiga?[2]

A. Fireshelpclearawayoldertrees,allowingyoungertreestotaketheirplaceB. RemovalofinvasivevegetationthatcompetewithconiferoustreesC. TheyallowgerminationofseedsthatonlyopenathightemperaturesD. Burningoforganicmatterinforestsoils,makingthemmorenutrient-rich

54.Deciduousforestsaroundtheworldharbormanyimportantspeciesintemperatezonesofclimate.Whichofthefollowingisanimportantecosystemservicethatforestsprovide?[2]

A. ReleaseofcarbondioxidethatmaketemperaturesmilderforanimalsB. ProvidingofshelterintreesthataremoreresistanttounusuallyhighwindsC. DistributionofnutrientsfromfrequentfiresduetodryvegetationD. Protectionoffreshwatersuppliesforanimalsandplants

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55.AsampleofsinglecelledmarinealgaeisolatedfromChesapeakeBayprovidedanestimateof230,000cellsontheinitialsamplingdate.Tendayslater,populationsizewasestimatedtobe980,000cells.Calculatethepopulation’sintrinsicrateofincrease.Includeunits.[3]

56.Batpopulationsaroundtheworldarethreatenedbywhitenosesyndrome(WNS),afungal

diseasethathascausedthesepopulationstobecomeverysmall.WhatisONEotherthreatbesidesdiseasethatthreatensthesurvivalofbatsiftheirnumbersremainsmall?[2]

A. CompetitionfromotherspecieswithsimilarnicheforlimitedresourcesB. LackofgeneticdiversityduetosmallgenepoolandbottleneckeffectC. IncreasedprobabilityofbecomingpreyforpredatorswithoutgroupsizeadvantageD. AlloftheaboveE. Noneoftheabove

57.Biogeochemicalcyclesinvolvethechangingdistributionsofchemicalelementsbetween

differentpartsoftheEarth,fromlivingtonon-living,andfromatmospheretolandandsea.Humanactivitieshaveacceleratedthesecyclesinrecentdecades,causingdramaticshiftsinthefluxesoftheseelementsandwheretheyendup.

i.Deforestationhasdevastatedthebalanceofcarbonontheplanet,beingthesecond

leadingcauseofrisingatmosphericCO2levelsbehindfossilfuelcombustion.Giventhisinformation,whatMAJORroledoforestsplayinthecarboncycle?[2]

ii.Thenitrogencyclealoneisresponsibleforatmosphericconcentrationsofthethree

mostimportanthuman-causedgreenhousegases.Namethesegases.[6]iii.Excessivenitratelevelsareoftenfoundinthegroundwaterofareaswithintensive

agriculture.Whichisanagriculturalpracticethatcancausesuchlevels?[2]A. ImproperconstructionormaintenanceofanimalwastelagoonsB. UseofammoniaindisinfectionofmeatproductsC. ApplicationofpesticidesonfieldsbeforeharvestingD. PlantingmonoculturesofGMOlegumeplantsforcrops

58.Fossilfuelcombustionhasbeenshowntoincreasethetotalconcentrationofcarboninthe

atmosphere.FromthefollowinghumanactivitieschoosetheTWOthatalsoincreasetheamountofcarbonthatisintheatmosphere.[4]

A. ManufacturingandprocessingofchemicalfertilizersandpesticidesB. Raisingcowsand/orruminantanimalsaslivestockC. PumpingofgroundwaterfromaquifersforfrackingD. TransportationwithprivatecarsandmotorizedvehiclesintocitycentersE. Constructionanduseoflandfillsthatproducecarbonby-products

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TiebreakerQuestion59.Populatedareaswithhighdegreesofurbanizationserveasacaseexampleofhowhuman

activitiescanprofoundlyimpacttheenvironment.NameTHREEenvironmentalproblems(besidesrunoffpollutionanduntreatedsewage)associatedwithextensivepavedareas.[6]

TiebreakerQuestion60.Asoneofthemostimportantbiogeochemicalcyclesontheplanet,thephosphoruscycleis

responsibleforthedistributionofelementalphosphorusinlivingorganisms.Withoutthepresenceofphosphorusintheenvironment,manyorganismscannotsurvive.

i. Onewayinwhichthephosphoruscycledifferssignificantlyfromthecarboncycle

isintermsofaccessibilityofnutrients.Asaresult,thephosphoruscycleismuchslowerthanthecarboncycle.Whyisitmuchmoredifficultforlivingorganismstoaccesselementalphosphorus?[2]

ii. Phosphorusasmentionedaboveisanecessaryelementrequiredfortheproper

survivalanddevelopmentofmostlivingorganisms,regardlessofenvironment.IdentifyTWOreasonswhyphosphorusissocrucialtomanyorganisms.[2]