For Office Use Only:
Score: _____ /180
Team Number:
____________
Team Name:
______________________________
Participant Names:
______________________________
______________________________
2016-2017 Ecology Exam
February 4, 2017
TeamNumber____Page1
SCIENCEOLYMPIADECOLOGY
PRINCETONINVITATIONAL2017
1. Rhizobiaarebacteriathatliveintherootnodulesofleguminousplantsandcanfix
atmosphericnitrogeninnitrogenouscompounds.Theplantscanusethesecompoundsin
theirmetabolism,whilethebacteriauseglucoseproducedbytheplants.Whatistheterm
thatbestdescribestherelationshipbetweenRhizobiumandtheplant?[2]
A. Parasitic
B. Mutualistic
C. Competitive
2. FishAisalargefishthatfeedsprimarilyonFishBandFishC.FishBlivesonphototrophic
plankton.FishClivesonzooplankton(whichconsumephototrophicplankton)andonFishD,
whichisanherbivore.
i.
Drawthefoodwebforthissituation.[5]
ii.
WhichlabelscanbeascribedtoFishAinthissituation?[2]
A. Producerandconsumer
B. Primaryandsecondaryconsumer
C. Secondary,tertiary,andquaternaryconsumer
D. Secondaryandtertiaryconsumer
3. Acanalhadalargepopulationofvariouskindsoffish.Afterfarmersintheareastarted
usingnitrogenousfertilizersontheirfields,rainwaterwashedexcessfertilizerintothecanal.
Afterafewdays,thenumberofalgaeinthepondincreasedgreatly,whilethelocalfish
populationdecreaseddramatically.
i.
Whatisthetermfortheprocessdescribedabovewherebyanincreaseinthe
availabilityofnutrientsresultedinanincreaseinalgae?[1]
ii.
Whymightthefishpopulationhavedecreased?NamethemainTWOfactors
thatcouldhavethisledtothisdecreaseandexplaintheeffectthesefactors
wouldhaveonthefishpopulation.[3]
iii.
Thepresenceofalgaeisabioticfactorinfluencingthefishpopulation.Name
ONEmorebioticandTWOabioticfactorsthatcaninfluencethefishpopulation.
[3]
4. Aplantisgrowinginamarshyarea.Theplantcannotgrowondrylandbecauseitneedsa
greatdealofwatertosurvive.However,itcannotgrowindeepwater.SuggestTWOmain
reasonswhytheplantmaybeabletogrowonlyinshallowwater.[4]
1OF13
TeamNumber____Page2
SCIENCEOLYMPIADECOLOGY
PRINCETONINVITATIONAL2017
Questions5-9dealwiththefollowinghypotheticalecologicalscenario:
Apopulationofdeerissuddenlyseparatedwhenahighwayisbuiltthatsplitsthepopulation’s
habitatintwo.Thetwogroupscannolongerreproducewithoneanother.Visioninthesedeer
isdeterminedbyallelesinasinglegene,withQbeingthedominantallele.Poorvisioninthese
deerisduetohomozygosityfortherecessivealleleq.
5. Whatkindofreproductivebarrierisrepresentedinthisscenario?[2]
A. Geographicisolation
B. Temporalisolation
C. Behavioralisolation
6. Mostdeerkeeptotheirnewhabitats;however,someindividualswithpoorvisionattempt
tocrossthehighway.Mostofthesedeerdieduetooncomingtraffic.Whatevolutionary
processdoesthisdemonstrate?Whatspecifictypeofthisprocessistakingplace?[4]
7. IftheprevalenceofalleleQinthetotalpopulationis63%andthepopulationisinHardyWeinbergequilibrium,whatpercentageofthepopulationpossessesthegenotypeQq?
Whatisthephenotypefordeerwiththisgenotype?[3]
8. Duetothedeathsofmanydeerwiththegenotypeqq,theprevalenceofalleleQinthe
populationincreases.Iftheprevalenceofalleleqis77%ofwhatitwasoriginally(inthe
situationdescribedinquestion5c),whatpercentageofdeernowhavegoodeyesight?
(AssumethattheonlyfactorinfluencingeyesightistheQgeneandthatthispopulationisin
Hardy-Weinbergequilibrium.)[3]
9. Aftermanyyears,thehighwayisabandonedandthetwopopulationsarereunited.
However,individualsarenowunabletobreedacrossthedifferentpopulations.Theycan
onlybreedwithindividualsfromtheirowngroup.Whatprocesshastakenplace?[2]
A. Speciation
B. Artificialselection
C. Geographicreproductivebarrier
D. Alienation
10.Certainfishspecieshavebecomeendangeredduetooverfishing.Ithasbeenmadeillegal
tofishforsomeofthesespecies.Still,theirpopulationscontinuetodecline.Suggesttwo
possiblereasonsthatthefishingindustryisstillcausingadeclineinthepopulationsofthese
fishspecies,eveniftheyarenotbeingfishedfor.(Writeonesentenceforeachreason.)[4]
2OF13
TeamNumber____Page3
SCIENCEOLYMPIADECOLOGY
PRINCETONINVITATIONAL2017
11.Thischartshowstherelativepopulationnumbersofthreespeciesofbacteriaintwo
differentcolonies.OnlytypesBandCwereintroducedtocolonyX,withaninitialratioof1:1
(theinitialrelativepopulationswere50forbothspecies).Allthreebacterialspecieswere
introducedtoColonyYina1:1:1ratio(i.e.initialrelativepopulationswere33forallspecies).
Population
BacteriumA
BacteriumB
BacteriumC
X
0
49
51
Y
97
2
1
Basedontheabovedata,whattypeofinteractionistakingplacebetweenbacterialspeciesA,B,
andC?Twoanswersarecorrect.[4]
A. BandCarebothpredatorstowardsA
B. BandCarebothcompetitorsofA
C. AisapredatorofbothBandC
D. BandChaveamutualisticrelationship
E. AandBhaveamutualisticrelationshipandarepredatorsofC
F. BandCcompetewitheachother
TiebreakerQuestion
12.Suggestasmanyobservationsasyoucanthatyouwouldseeinanareawhereecological
successionistakingplace.[5]
TiebreakerQuestion
13.Namethetwobiogeochemicalcyclesshown.Foreachofthesecycles,statetheglobal
humanactivitythatmostimpactsitandhowtheactivitycontributestoclimatechange.[6]
3OF13
TeamNumber____Page4
SCIENCEOLYMPIADECOLOGY
PRINCETONINVITATIONAL2017
Questions14-19dealwiththefollowingbiomemapbelow:
14.Whattypesofleafshapesareoftenfoundontreesinthebiomethatiscoloredblue?[2]
A. Obovate
B. Lance-shaped
C. Needleleaf,conical
15.Inthebiomethatiscoloreddarkpurplenearthetop,whatistheprimarychallengefaced
byvegetationthatlimitsthemaximumheighttowhichtheycangrow?[2]
A. Lackofsunlightforabouthalftheyear
B. Lowfertilesoilcontentduetopermafrost
C. Thicklayersofsnowcoverinwinter 16.Namethreephysicaladaptationsthatmammalsintheblue-coloredbiomeusuallypossess
forsurvivalinthewinterseason.[3]
17.Animalsinthepurple-coloredbiomeoftenexhibittwobehavioraladaptationsthathelp
themsurvivewinterconditionsintheirenvironment.Namethesetwobehaviors.[2]
18.Thebiomeshowninbrightredisatypeofforestthatisuniquefromotherforestbiomes
duetooneadaptationsharedbyitstrees.Namethatoneadaptation.[1]
19.Howdoesthisoneadaptation,sharedbymostplantsinthebiomeshowninred,contribute
tothehighspeciesrichnessofthebiome?[2]
4OF13
TeamNumber____Page5
SCIENCEOLYMPIADECOLOGY
PRINCETONINVITATIONAL2017
20.Duetotheextremeconditionsoflowtemperatureandprecipitationintaigaecosystems,
thesoilcantakeonuniqueproperties,formingaspecialorganicsubstancethatisfoundall
aroundthetaiga.Whatisthisspecialmattercalled?[2]
A. Permafrost
B. Greenmanure
C. Muskeg
D. Compost
21.Whichofthechoicesliststwoadaptationsthatallowvegetationinborealforeststoendure
theharshclimateofthetaigaecosystem?[2]
A. Perennialplantgrowth;seasonalleafchanges
B. Darkcolorofleaves;yearlongretentionoffoliage
C. C4photosynthesispathway;bushygrowthclosetotheground
D. Antifreezeproteins;large,thinleavesforsunlightabsorption
22.Certainplantspeciesinthetaigabiomelikethedominantwhitespruceandbalsamfironly
appearintheecosystemmanyyearsafteramajordisturbanceintheenvironmentoccurs,
suchasnaturaldisasters.Manyofthesespeciesarealsonotresistanttodisturbances,being
amongthelasttocolonizeahabitat.
i. Whatisthetermforthetypeofsuccessionalcommunitythatmanyoftheseplants
wouldbelongto,whichoccursatthepeakperiodforanecologicalcommunity?[2]
A. Climaxcommunity
B. Seralcommunity
C. Primarycommunity
D. Secondarycommunity
ii. Wouldthisecologicalstatebeachievedthroughprimarysuccessionorsecondary
succession,orboth?[2]
iii. Certaindisturbanceforcesareimportantformaintainingthediversityofspeciesin
anecosystem.Whichnaturalforceisparticularlyusefulforplantthinning?[1]
23.Thetundraisknownforbeingaharshbiomewithlittlevegetativematterandnotablefor
thelackoftreesduetoitsharshenvironmentalextremes.Whichofthefollowingisatraitthat
isexclusivelydistinguishingofthetundra?[2]
A. Vegetationthatonlygrowsclosetotheground
B. Lowtemperaturesandprecipitationduetocoldairandhighlatitudes
C. Unevendistributionofsunlightthatdeprivesplantsofenergy
D. Shortsummersandlongwinters
5OF13
TeamNumber____Page6
SCIENCEOLYMPIADECOLOGY
PRINCETONINVITATIONAL2017
24.Afisheriesbiologistwishestooptimizeheryieldbymaintainingapopulationoftroutat
exactly1000individuals.Predicttheinitialinstantaneousgrowthrateifthepopulationis
stockedwithanadditional700fish.Assumeris0.008individuals/(individual*day).[2]
A. -2.04individualsperday
B. 3.72individualsperday
C. 2.04individualsperday
D. -1.28individualsperday
25.Supposethatapopulationofalligatorsisgrowingaccordingtothelogisticcurveequation.If
thecarryingcapacityis260alligatorsandr=0.05individuals/(individual*month),whatis
themaximumpossiblegrowthrateforthisspecificpopulation?[2]
A. 3.25individualspermonth
B. 3.01individualspermonth
C. 1.04individualspermonth
D. 1.76individualspermonth
Questions26-28refertothegroupofsurvivorshipcurvesbelow:
AnswereachquestionwithTypeI,TypeII,orTypeIIIastheanswer.[2pointsperquestion]
26.Whichofthesurvivorshipcurvesinthegraphistypicallyobservedinsomelizardspecies?
27.Characteristicofspeciesthatexhibitr-selectionstrategyinproductionofoffspring
28.Typicalforrelativelylargespeciesthatproducefewoffspringbutcareforthemwellin
intimateparentalrelationships
6OF13
TeamNumber____Page7
SCIENCEOLYMPIADECOLOGY
PRINCETONINVITATIONAL2017
29.Asaratherunforgivinglocationforlifetodevelop,thetundrahasforcedthefewplantsthat
cansurviveitsharshconditionstotakeonvariousadaptations.
i. Whichofthefollowingisaproperadaptationthatcontributestoaplant’syearlong
survivalinthetundrabiome?[2]
A. Conicalleafshapes
B. Shadetolerancetocopewithlowlightlevels
C. Brightlycoloredfoliagewithseasonalvariations
D. Perennialplantgrowth
ii. Manynativetypesoftundravegetationarechamaephytes,whichmeansthatthey
__________tothegroundinordertoavoidhigh________.[4]
30.Whatdoestheterm“deciduous”mean,andhowdoesitrelatetodescribingtheoverall
climatepatternsofthedeciduousforestbiome?[2]
A. Tofallofforshed;suggestsmildseasonalweatherpatternsleadingtopredictable
changesinbothtemperatureandprecipitation
B. Referstoplantsthatloseleavesseasonally;suggeststwolongseasons:wetanddry
C. Dominatedbygrasses;suggestsmildclimatepatternsthatoccurincycles
D. Possessesbudsthathibernateinwinter;suggestshighprecipitationatconstant
levelsthroughtheseasonsandretentionoffoliageyear-round
31.Inatypicaldeciduousforestbiome,howmanydistinctseasonsareobservedthroughout
thecourseofatypicalyear?[2]
A. Twoseasons
B. Fourseasons
C. Oneseason
D. Threeseasons
32.Deciduousforestshaveamoreabundantassemblageoflifeintheirecosystemsranging
frommanyspeciesofforestwildlifelikedeer,raccoons,andbirdstomanykindsofplants
fromshrubsandundergrowthtohardwoodtrees.Fromthefollowingfactors,choosethe
TWOthatareMOSTresponsibleforthisdiversityofspeciesandtheirdistribution.[4]
A. Lowtemperaturesbelowfreezing
B. Successivechangingoftheseasonsonadefinedcycle
C. Moderateamountsofprecipitationthroughouttheyear
D. Availabilityofabundantfoodfromstandingtrees
E. Seasonalappearanceanddisappearanceoftheforestcanopy
7OF13
TeamNumber____Page8
SCIENCEOLYMPIADECOLOGY
PRINCETONINVITATIONAL2017
33.Biodiversityoflandspecies,especiallyinthetropics,hasbeenthreatenedforyearsby
humanactivitiesofdeforestationandindustrializedagriculture.Despiteeffortstocutback
onsuchdestructiveactivities,manyspeciesremainthreatened.Whataretwootherareas
ofhumanimpactthatmaycontributetothecontinueddeclineofglobalbiodiversity?[2]
A. Overgrazingbylivestock;globalcoolingthroughvolcanoes
B. Emissionofgreenhousegases;replantingtreesinnewgrowthforests
C. Introductionofinvasivespecies;useofchemicalfertilizersandpesticides
D. Recyclingofusedmaterials;recreationalhuntingofendangeredspecies
34.Windsinthetundraoftenreachspeedsofupto______mph.[2]
A. 10-20
B. 50-80
C. 10-30
D. 30-60
E. Noneoftheabove
35.Lossofprotectivevegetationposesseriousrisksforthehealthoftheecosystemsthatthey
wereformerlylocatedin,suchassoilerosion,aprocessthatcanleadtothedeteriorationof
soilqualityinanenvironmentanditsecologicalwell-beingoveryears.
i. Whataretwofactorsthatexplainhowvegetationcoveroccupiesanimportantrole
inpreventingexcessivesoilerosion?ChoosethebestTWO.[4]
A. Slowingdownofsurfacerunofffromrainstorms
B. Attractivenesstolargeanimalsforshelter
C. Highcompetitionamongspeciesforsunlight
D. Rootsholdingdownsoiltopreventitfromwashingaway
E. Storageofsugarsandstarchesintubers
ii. Whichofthefollowingmajorhumanactivitiesdisruptsthehealthofvulnerable
naturalenvironmentsthroughthestrippingofvegetation?[2]
A. Constructionofdamsalongmajorrivers
B. Stripminingforpreciousmetalsandminerals
C. Deforestationthroughslash-and-burnagriculture
D. Emissionofgreenhousegassesfromburningoffossilfuels
36.Inspiteofthegrowingriskofsoilerosioninhabitatsandenvironmentsaroundtheworld
withincreasinghumanactivity,thereareconcretemethodsthathavebeendevelopedinrecent
yearstocombatsoilerosionandminimizeitsdamage.NameTWOsuchpractices.[4]
8OF13
TeamNumber____Page9
SCIENCEOLYMPIADECOLOGY
PRINCETONINVITATIONAL2017
Questions37-43refertothefollowingexponentialandlogisticgrowthcurvesbelow.Answer
eachquestionwiththeletterreferringtothepartofthegraphthatbestfitseachdescription.
[2pointsperquestion]
C
D
B
A
37.Phasewheretheinstantaneousgrowthforapopulationthatfollowsapatternoflogistic
growthreachesitsmaximumvalue
38.Pointwherepopulationsthataresubjecttodensity-dependentgrowthfactorsreachthe
limitsatwhichtheirenvironmentscanadequatelysupportallindividuals
39.Stageatwhichtherateofgrowthbeginstodecreaseinmagnitudeasthefiniteamountof
resourcesofanecosystemareexhaustedbyagrowingpopulation
40.Initialstageduringwhichpopulationsstarttoexpandfromafewselectindividualsasthey
taketimetodeveloppriortoreproduction
41.Pointatwhichintraspecificcompetitionoccurs,leadingtonaturalselectionasindividuals
whohavedifferentadaptationstotheirenvironmentcompetewitheachotherforsurvival
42.Constantlyexpandinggrowthratethatischaracteristicofanexponentialgrowthpattern
startsfromthisphasewithfewindividualsgrowingslowlydespiteabundanceofresources
43.Divergencesbetweenexponentialandlogisticgrowthcurvesbecomeprominentfromthis
phase,allowingthedevelopmentofcharacteristicS-shapecurve
9OF13
TeamNumber____Page10
SCIENCEOLYMPIADECOLOGY
PRINCETONINVITATIONAL2017
44.Theprimarystagesofthenitrogencycleare(startingwithatmosphericN2):[2]
A.ammonification,denitrification,nitrogenfixation,nitrification,assimilation
B. nitrogenfixation,ammonification,assimilation,nitrification,phosphorylation
C. respiration,decarboxylation,quantification,nitrification,assimilation
D. nitrogenfixation,nitrification,assimilation,respiration,ammonification
E. nitrogenfixation,nitrification,assimilation,ammonification,denitrification
45.Septicwatersystemsareoftencontaminatedwithbacteriafromanimalwaste.Suppose
thatawatertankisinfestedwithacolonyof80,000E.colibacteria.Ifthenumberof
bacteriapresentinthetankafter10daysis190,000,determinethedoublingtime.[2]
46.Whichofthefollowingbestdescribesarelationshipinwhichtwospeciesbothmutually
benefitfromeachother’sbehaviors?[2]
A. Symbiosis
B. Competition
C. Parasitism
D. Commensalism
E. Mutualism
47.Whenresourcesareabundantandtheenvironmentisstable,whichreproductivestrategy
wouldbemosteffectiveforspeciessurvival?[2]
A. Asexualreproductionthroughbudding
B. Sexualreproduction,withminimalparentalcareandrapiddevelopmenttomaturity
C. Sexualreproduction,withintimateparentalcareandslowdevelopmenttomaturity
D. Alloftheabove
E. Noneoftheabove
48.AhealthypopulationofDouglasfir,aperennialevergreentree,increasesby13%peryear.
Calculatethedoublingtimeforthispopulation.Includeunits.[2]
49. Abouthowmuchenergyislostbetweeneachsuccessivetrophiclevelofatypicalenergy
pyramidforadevelopedecosystem?[2]
A. 10%
B. 50%
C. 90%
D. 99%
E. noneoftheabove
10OF13
TeamNumber____Page11
SCIENCEOLYMPIADECOLOGY
PRINCETONINVITATIONAL2017
50.Thetotalamountofenergycontainedatthefirsttrophiclevelthatisavailabletothefirst
levelofconsumersinanyecosystemiscalled:[2]
A. energytransfer
B. netprimaryproduction
C. grossprimaryproduction
D. carbonfixation
E. 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,allowingyoungertreestotaketheirplace
B. Removalofinvasivevegetationthatcompetewithconiferoustrees
C. Theyallowgerminationofseedsthatonlyopenathightemperatures
D. Burningoforganicmatterinforestsoils,makingthemmorenutrient-rich
54.Deciduousforestsaroundtheworldharbormanyimportantspeciesintemperatezonesof
climate.Whichofthefollowingisanimportantecosystemservicethatforestsprovide?[2]
A. Releaseofcarbondioxidethatmaketemperaturesmilderforanimals
B. Providingofshelterintreesthataremoreresistanttounusuallyhighwinds
C. Distributionofnutrientsfromfrequentfiresduetodryvegetation
D. Protectionoffreshwatersuppliesforanimalsandplants
11OF13
TeamNumber____Page12
SCIENCEOLYMPIADECOLOGY
PRINCETONINVITATIONAL2017
55.AsampleofsinglecelledmarinealgaeisolatedfromChesapeakeBayprovidedanestimate
of230,000cellsontheinitialsamplingdate.Tendayslater,populationsizewasestimated
tobe980,000cells.Calculatethepopulation’sintrinsicrateofincrease.Includeunits.[3]
56.Batpopulationsaroundtheworldarethreatenedbywhitenosesyndrome(WNS),afungal
diseasethathascausedthesepopulationstobecomeverysmall.WhatisONEotherthreat
besidesdiseasethatthreatensthesurvivalofbatsiftheirnumbersremainsmall?[2]
A. Competitionfromotherspecieswithsimilarnicheforlimitedresources
B. Lackofgeneticdiversityduetosmallgenepoolandbottleneckeffect
C. Increasedprobabilityofbecomingpreyforpredatorswithoutgroupsizeadvantage
D. Alloftheabove
E. Noneoftheabove
57.Biogeochemicalcyclesinvolvethechangingdistributionsofchemicalelementsbetween
differentpartsoftheEarth,fromlivingtonon-living,andfromatmospheretolandandsea.
Humanactivitieshaveacceleratedthesecyclesinrecentdecades,causingdramaticshiftsin
thefluxesoftheseelementsandwheretheyendup.
i.Deforestationhasdevastatedthebalanceofcarbonontheplanet,beingthesecond
leadingcauseofrisingatmosphericCO2levelsbehindfossilfuelcombustion.Given
thisinformation,whatMAJORroledoforestsplayinthecarboncycle?[2]
ii.Thenitrogencyclealoneisresponsibleforatmosphericconcentrationsofthethree
mostimportanthuman-causedgreenhousegases.Namethesegases.[6]
iii.Excessivenitratelevelsareoftenfoundinthegroundwaterofareaswithintensive
agriculture.Whichisanagriculturalpracticethatcancausesuchlevels?[2]
A. Improperconstructionormaintenanceofanimalwastelagoons
B. Useofammoniaindisinfectionofmeatproducts
C. Applicationofpesticidesonfieldsbeforeharvesting
D. PlantingmonoculturesofGMOlegumeplantsforcrops
58.Fossilfuelcombustionhasbeenshowntoincreasethetotalconcentrationofcarboninthe
atmosphere.FromthefollowinghumanactivitieschoosetheTWOthatalsoincreasethe
amountofcarbonthatisintheatmosphere.[4]
A. Manufacturingandprocessingofchemicalfertilizersandpesticides
B. Raisingcowsand/orruminantanimalsaslivestock
C. Pumpingofgroundwaterfromaquifersforfracking
D. Transportationwithprivatecarsandmotorizedvehiclesintocitycenters
E. Constructionanduseoflandfillsthatproducecarbonby-products
12OF13
TeamNumber____Page13
SCIENCEOLYMPIADECOLOGY
PRINCETONINVITATIONAL2017
TiebreakerQuestion
59.Populatedareaswithhighdegreesofurbanizationserveasacaseexampleofhowhuman
activitiescanprofoundlyimpacttheenvironment.NameTHREEenvironmentalproblems
(besidesrunoffpollutionanduntreatedsewage)associatedwithextensivepavedareas.[6]
TiebreakerQuestion
60.Asoneofthemostimportantbiogeochemicalcyclesontheplanet,thephosphoruscycleis
responsibleforthedistributionofelementalphosphorusinlivingorganisms.Withoutthe
presenceofphosphorusintheenvironment,manyorganismscannotsurvive.
i.
Onewayinwhichthephosphoruscycledifferssignificantlyfromthecarboncycle
isintermsofaccessibilityofnutrients.Asaresult,thephosphoruscycleismuch
slowerthanthecarboncycle.Whyisitmuchmoredifficultforlivingorganismsto
accesselementalphosphorus?[2]
ii.
Phosphorusasmentionedaboveisanecessaryelementrequiredfortheproper
survivalanddevelopmentofmostlivingorganisms,regardlessofenvironment.
IdentifyTWOreasonswhyphosphorusissocrucialtomanyorganisms.[2]
13OF13