NEETREVISIONSERIES

ECOSYSTEM

ReviseMostImportantQuestionstoCrackNEET2020

DownloadDoubtnutNow

Q-1-14538154

Which of the following pairs is not correct?

(A)

(B)

(C)

(D)Noneofthese

CORRECTANSWER:D

WatchVideoSolutionOnDoubtnutApp

E.Haecker − coinedtheterm,Ecology

tansley − Coinedtheterm'Ecosystem

R.Mishra − FatherofindianEcology

Q-2-41231075

Which is not true regarding ecosystem?

(A)Self-sufficientunit.

(B)Cyclicexchangeofmaterialsbetweenlivingbeings

andenvironment

(C)Onlyrequirementisinputofenergy.

(D)Characterizedbyamajorvegetationtype.

CORRECTANSWER:D

WatchVideoSolutionOnDoubtnutApp

Q-3-55657920

The study of interaction between groups of various organisms with

their environment is

(A)ecology

(B)zoogeography

(C)synecology

(D)systembiology

CORRECTANSWER:C

WatchVideoSolutionOnDoubtnutApp

Q-4-14538155

Vertical distribution of different species occupying different levels

in dense vegetation is called

(A)stratification

(B)speciescompositon

(C)standingcrop

(D)trophicstructure.

CORRECTANSWER:A

SOLUTION:

Verticaldistributionofdifferentspeciesoccuping

differentlevelsiscalledstratification.Forexample,trees

occupytopverticalstrataorlyaerofaforest,shrubsthe

secondandherbsandgrassesoccupythebottom

layers.

WatchVideoSolutionOnDoubtnutApp

Q-5-41231077

The amount of living material and nutrients present in different

trophic levels and soils at any given time are called, respectively.

(A)Standingstateandstandingcrop

(B)Standingcropandstandingstate

(C)Standingstateandstandingquality

(D)Biomassandstandingcrop

CORRECTANSWER:B

WatchVideoSolutionOnDoubtnutApp

Q-6-41231239

Secondary productivity is rate of formation of new organic matter

by:

(A)Producer

(B)Parasite

(C)Consumer

(D)Decomposer

CORRECTANSWER:C

WatchVideoSolutionOnDoubtnutApp

Q-7-55657897

The term Homeostasis in an ecosystem refers to

(A)Feedbackmechanism

(B)Selfregulatorymechanism

(C)Influenceofproduction

(D)Stateofequilibrium

CORRECTANSWER:D

SOLUTION:

Homeostasisorstateofequilibriumorbalanceofnature

ismaintainedthroughanumberofcontrolslikecarrying

capacity,selfregulationandfeedbacksystem.

WatchVideoSolutionOnDoubtnutApp

Q-8-14538167

The rate of formation of new organic matter by rabbit in a

grassland, is called.

(A)netproductivity

(B)secondaryproductivity

(C)Netprimaryproductivity

(D)grossprimaryproductivity.

CORRECTANSWER:B

SOLUTION:

Sincerabbitisaconsumertherfore,therateofformation

ofneworganicmatterbyrabbitinagrasslandiscalled

secondaryproductivity.

WatchVideoSolutionOnDoubtnutApp

Q-9-14538161

The rate of conversion of light energy into chemical energy of

organic molecules in an ecosystem is

(A)netprimaryproductivity

(B)grossprimaryproductivity

(C)secondaryproductivity.

(D)grosssecondaryproductivity.

CORRECTANSWER:B

WatchVideoSolutionOnDoubtnutApp

Q-10-14538164

The biomass available for consumption by the herbivores and the

decomposers is called

(A)netprimaryproductivity

(B)secondaryproductivity

(C)standingcrop

(D)grossprimaryproductivity.

CORRECTANSWER:A

SOLUTION:

Theamountofenergyaccumulationingreenplantsas

biomassororganicmatterperunitareaoveratime

periodisknownasprimaryproductivity.Therateoftotal

captureofenergyortherateoftotalproductionof

organicmaterial(biomass)duringphotosynthesis,is

knowasgrossprimaryproductivity,However,whilethe

energycapturingprocessisoperatinginthegreen

tissues,theseaswellasothertissuesareconsuming

energyinrespiration.Thebalanceenergyorbiomass

remainingaftermeetingthecostofrespirationof

producers,iscallednetprimaryproductivity.

Netprimaryproductivity=Grossprimaryproductivity-

Respirationrate

Thenetprimaryproductivityresultsintheaccumulation

ofplantbiomass,whichservesasthefoodofherbivores

anddecomposers.

WatchVideoSolutionOnDoubtnutApp

Q-11-41231256

The primary producers of the deep-sea hydrothermal vent

ecosystem are:

(A)Blue-greenalage

(B)Coralreefs

(C)Greenalgee

(D)Chemosyntheticbacteria

CORRECTANSWER:A

WatchVideoSolutionOnDoubtnutApp

Q-12-14538249

An ecosystem which can be easily damaged but can recover after

some time if damaging effect stops, will ba having.

(A)lowstabilityandhighresilience

(B)highstabilityandlowresilience

(C)lowstatbilityandlowresilience

(D)highstabilityandhighresilience.

CORRECTANSWER:A

SOLUTION:

Ifanecosystemiseasilydameged,thatmeansitisnot

verystable.Butsince,itrecoversfastwhenthe

damagingeffectstops,itcertainlyhashighresilience.

WatchVideoSolutionOnDoubtnutApp

Q-13-41231249

Rachel Carson's famous book "Silent Spring" is related to:

(A)Ecosystemmanagement

(B)Pesticidepollution

(C)Noisepollution

(D)Populationexplosion

CORRECTANSWER:C

WatchVideoSolutionOnDoubtnutApp

Q-14-14538233

The rate of secondary succession is faster than primary succession

because.

(A)soilorsedimentisalreadypresent

(B)waterisavailbaleinlargequantity

(C)climaxcommunityisalreadypresent

(D)pHofsolisfavorable.

CORRECTANSWER:A

WatchVideoSolutionOnDoubtnutApp

Q-15-55657915

The second stage of hydrosere is occupied by plants like

(A)Salix

(B)Vallisneria

(C)Azolla

(D)Typha

CORRECTANSWER:B

SOLUTION:

Thesecondstageofhydrosereisoccupiedby

submergedaquaticplantse.g.,Hydrilla,Vallisneria.The

thirdstagehasfreefloatingplantse.g.,Azolla(floating

aquaticfern).ThefourthstageisReedSwampplants

likeTypha.Salixincludesdeciduoustreesandshrubs

whichconstitutethesixth(woodlandstage)andclimax

stages.

WatchVideoSolutionOnDoubtnutApp

Q-16-41231102

Ecological pyramids are also called

(A)Pyramidofnumber

(B)Eltonianpyramids

(C)Pyramidsofenergy

(D)Pyramidsofbiomass

CORRECTANSWER:B

WatchVideoSolutionOnDoubtnutApp

Q-17-55657891

Choose the area which will take minimum time for succession.

(A)NewlyCooledlava

(B)Newlycreatedpond

(C)Abandonedfarmland

(D)Barerock

CORRECTANSWER:C

WatchVideoSolutionOnDoubtnutApp

Q-18-14538236

Which of the following is considered as pioneer community is

xerarch?

(A)Annulaherbs

(B)Perennialherbs

(C)Shurbs

(D)Lichens

CORRECTANSWER:D

WatchVideoSolutionOnDoubtnutApp

Q-19-42131104

int(1+x^(2))cos2xdx

WatchVideoSolutionOnDoubtnutApp

Q-20-14538289

An inverted pyramid of biomass can be found in which ecosystem?

(A)Forest

(B)Marine

(C)Grassland

(D)Tundra

CORRECTANSWER:B

SOLUTION:

Inanaquaticecosystem,producershaveleastbiomass

andthisvaluegradullyshowsanincreasetowardsthe

apexofthepyramid,thusmakingthepyramidinvertedin

shape.Biomassbasicallydependsuponreproductive

potentialandageofindividuals.

WatchVideoSolutionOnDoubtnutApp

Q-21-55657857

Putrefying organisms are

(A)producerorganisms

(B)reducerorganisms

(C)consumerorganisms

(D)parasiticorganisms

CORRECTANSWER:B

WatchVideoSolutionOnDoubtnutApp

Q-22-14538181

The ultimate energy source of all ecosystem is

(A)producers

(B)organicmolecules

(C)carbohydrate

(D)solarradiation.

CORRECTANSWER:D

WatchVideoSolutionOnDoubtnutApp

Q-23-41231123

The pyramid of energy in a forest ecosystem is:

(A)Alwaysupright

(B)Alwaysinverted

(C)Bothuprightandinverted

(D)Noneoftheabove

CORRECTANSWER:A

WatchVideoSolutionOnDoubtnutApp

Q-24-14538293

Pyramid of numbers is

(A)alwaysupright

(B)alwaysinverted

(C)eitheruprightorinverted

(D)neitheruprightnorinverted.

SOLUTION:

Ecologicalpyramidsarepictorialrepresentationof

relationshipbetweenorganismsatdifferenttrophic

levels,regardingenergy,biomassornumber.Pyramidof

numberscanbeeitheruprightorinverted.Forexample,

inagrasslandecosystem,pyramidofnumberwillbe

uprightbecausenumberofprimaryconsumersareless

thanprimaryproducersandthatofsecondary

consumersarelessthanprimaryconsumersandsoon.

Ontheotherhand,inaparasiticfoodchainthepyramid

ofnumberwillbeinverted.

WatchVideoSolutionOnDoubtnutApp

Q-25-41231122

Which of the following is the most productive ecosystem?

(A)Estuary

(B)Opensea

(C)Desert

(D)Mountain

CORRECTANSWER:A

WatchVideoSolutionOnDoubtnutApp

Q-26-14538174

Fragmentation, leaching and catabolism are some of the important

steps of decompositon. Study the following statements I , ii and iii

regarding these and select the correct option.

(i) Detritivores (e.g., earthworm) breakdwon detritus into smaller

particles.

(ii) Water soluble inorganic nutrients go down into soil horizon and

get precipitated as unavailable salts.

(iii) Decomposers (e.g., bacteria and fungi) secrete digestive

enzymes and degrade detritus into simpler inorganic substances.

(A)

(B)

Leaching Fragmentation Catabolism(i) (ii) (iii)

Leaching Fragmentation Catabolism(iii) (ii) (i)

(C)

(D)

CORRECTANSWER:C

SOLUTION:

Theprocessofdecompositioncanbecategorisedas

fragmentationofdetritus,leachingandcatabolism.

Fragmentationofdetritusistheprocessthatcauses

breakdownofdetritusintosmallerparticles.Itisprimarily

duetotheactionofdetritusfeedinginvertebrates

(detritivores,e.g.,termites,earthworms,etc.).The

detritusgetspulverisedwhenpassingthroughthe

digestivetractsofanimals.Duetofragmentation,the

Leaching Fragmentation Catabolism(ii) (i) (iii)

Leaching Fragmentation Catabolism(ii) (iii) (i)

surfaceareaofdetritusparticlesisgreatlyincreased.

Theextracelluarenzymesreleasedbybacteriaandfungi

carryoutcatabolism,i.e.,enzymaticconversionofthe

decomposingdetritustosimplerandinorganic

substances.Leachingistheprocessbywhichdissolved

nutrientsaremovedintolowerlayersofsoilor

groundwatertoformunavailablesalts.

WatchVideoSolutionOnDoubtnutApp

Q-27-14538179

Rate of decompositon depends upon

(A)chemicalcompositonofdetritus

(B)temperature

(C)soilmoistureandsoilpH

(D)allofthese.

CORRECTANSWER:D

SOLUTION:

Rateofdecompositionofdetritusdependsupon

chemicalnatureofdetritus,temperature,soilmoisture

andsoilpH.Asoiltemperatureof andmore

hastensdecomposition.Alowtemperatureoflessthan

reducesrateofdecomposition.Moistureis

essentialfordecomposition.Excessivemoisturealso

impedesdecompositionprobablyduetoanaerobiosis.

Neutralandslightlyalkalinesoilsarerichindetritivores,

earthwormsanddecomposermicrobes.Acidity

decreasesthenumberofdetritivoresandearthworms.

Soilwithsmallamountoflignin/chitin/celluloseandrich

innitrogenandwatersolublesubstances(likesugars),

decomposesrapidly

25C

10C

WatchVideoSolutionOnDoubtnutApp

Q-28-41231126

The number of primary producers within a specified area would be

maximum in:

(A)Grasslandecosystem

(B)Forestecosystem

(C)Pondecosystem

(D)Deserts

CORRECTANSWER:C

WatchVideoSolutionOnDoubtnutApp

Q-29-14538206

Which kind of pyramid is represented by the given figure?

(A)Pyramidofnumbersinterrestrialecosystem

(B)Pyramidofbiomassinterrestrialecosystem

(C)Pyramidofbiomassinaquaticecosystem

(D)Pyramidofnumbersinaquaticecosystem

CORRECTANSWER:C

WatchVideoSolutionOnDoubtnutApp

Q-30-41231118

Which is not a characteristic of sera stages?

(A)Simplifiedfoodchain

(B)Fewandgeneralizedniches

(C)LowNPP

(D)Lowenergyuseefficiency

CORRECTANSWER:C

WatchVideoSolutionOnDoubtnutApp

Q-31-14538171

Which one of the following is the most productive ecosystem?

(A)Temperateforest

(B)Grasslands

(C)Desert

(D)Tropicalrainforest

CORRECTANSWER:D

SOLUTION:

Tropicalrainforestshowsthemaximumdiversityand

alsothemaximumproductivity.Moresolarenergyand

resourcesareavailableintropicswhichpromoteshigher

productivity.Onlandthemaximumprimaryproduction

rateisfoundintropicalrainforestsfollowedbytropical

deciduousforests,temperateforests,savannah,

temperategrasslandsanddesertscrub.

WatchVideoSolutionOnDoubtnutApp

Q-32-41231086

NPP is given by the formula

(A)NPP=

(B)NPP=GDP-Secondaryproductivity

(C)NPP=GPP-Respirationrate

(D)NPP=

GPP × 100

GPP/100

CORRECTANSWER:C

WatchVideoSolutionOnDoubtnutApp

Q-33-41231186

Carbon cycle includes (the following is a logical sequence)

(A)

(B)

(C)

(D)

Producer→ Consumer→ Decomposer

Decomposer→ Consumer→ Producer

Producer→ Decomposer→ Consumer

CORRECTANSWER:A

WatchVideoSolutionOnDoubtnutApp

Q-34-14538197

In an aquatic ecosystem, the organism present at the trophic level

equivalent to cows in grasslands is

(A)phytoplanktons

(B)largefishes

(C)seagulls

(D)zooplanktons.

CORRECTANSWER:D

Consumer→ Producer→ Decomposer

SOLUTION:

Inandaquaticecosystem,theimportantherbivoresare

zooplankton,larve,tadpoles,etc.Cowsingrasslands

alsoactasherbivoresasthesefeedonproducers.Thus,

bothcowsandzooplanktonoccupysecondtrophiclevel

interrestrialandaquaticecosytemrepectively.

WatchVideoSolutionOnDoubtnutApp

Q-35-41231247

The mass of living material at a trophic level at a particular time is

called:

(A)Standingcrop

(B)Grossprimaryproductivity

(C)Standingstate

(D)Netprimaryproductivity

CORRECTANSWER:A

WatchVideoSolutionOnDoubtnutApp

Q-36-14538251

All type of successions leads to

(A)xericclimaxcommunityq

(B)hydricclimaxcommunity

(C)mesicclimaxcommunity

(D)anyclimaxcommunitydependingonnatureof

habitat.

CORRECTANSWER:C

SOLUTION:

Alltypeofsuccessionswheathertakingplaceinwateror

onland,proceedstoasimilarclimaxcommunity,i.e.,

mesic.

WatchVideoSolutionOnDoubtnutApp

Q-37-41231253

Which of the following is a characteristic feature of cropland

ecosystem

(A)Absenceofsoilorganisms

(B)Leastgeneticdiversity

(C)Absenceofweeds

(D)Ecologicalsuccession

CORRECTANSWER:B

WatchVideoSolutionOnDoubtnutApp

Q-38-14538242

Select the correct sequence of succession in a pond.

(A)Submergedplants Floatingplants Reed

swampstage Sedges

(B)Floatingplants Submergedplants redd

swampstage Sedges

(C)Reedswampstage Sedges Floatingplants

Submergedplants

(D)Sedges Reedswampstage Floatingplants

Submergedplants

CORRECTANSWER:A

SOLUTION:

Seriesofbioticcommunitiesthatdevelopinanewly

→ →

→

→ →

→

→ →

→

→ →

→

formedpondorlakeiscalledhydrosere.Variousseral

stagesofhydrosereare:

Planktons(phytoplanktonsandzooplanktons)

rootedsubmergedhydrophytes reedswamps

sedgesormarsh-meadowstage woodlandorscrub

stage climaxforest.

WatchVideoSolutionOnDoubtnutApp

Q-39-41231245

Secondary/Succession takes place on/in :

(A)Newlycooledlava

(B)Barerock

(C)Degradedforest

(D)Newlycreatedpond

→

→ →

→

→

CORRECTANSWER:C

WatchVideoSolutionOnDoubtnutApp

Q-40-41231250

Most animals that live in deep oceanic waters are:

(A)Detritivores

(B)Primaryconsumers

(C)Secondaryconsumers

(D)Tertiaryconsumers

CORRECTANSWER:C

WatchVideoSolutionOnDoubtnutApp

Q-41-14538257

Select the pairs of sediamentary biogeochemical cycles.

I. Hydrogen cycle and water cycle

II. Phosphorus cycle and sulphur cycle

III. Calcium cycle and magnesium cycle

IV. Carbon cycle and nitrogen cycle

(A)IandII

(B)IIandIII

(C)IIIandIV

(D)IandIV

CORRECTANSWER:B

SOLUTION:

Biogeochemicalcyclescanbegroupedinto2types:

(i)Gaseouscycle:Materialinvolvedincirculationare

gasesorvapoursandthereservoirpoolisthe

atmosphereorhydrosphere,e.g.,nitrogen,carbon,

hydrogen,oxygenandwatercycle.

(ii)Sedimenatrycycle:Materialsinvolvedincirculation

arenon-gaseousandthereservoirpoolislithosphere,

e.g.,phosphrorus,sulphur,calciumandmagnesium

cycle.

WatchVideoSolutionOnDoubtnutApp

Q-42-55657868

Ecological efficiency is

(A)Foodprimaryassimilated/Foodenergyingested

(B)Grossprimaryproductivity/Incidenttotalsolar

radiation

(C)Volumeof evolved/volumeof consumed

(D)Energyinbiomassproductionatatrophic

× 100

× 100

CO2 O2

level/Energyinbiomassproductionatprevioustrophical

level

CORRECTANSWER:D

WatchVideoSolutionOnDoubtnutApp

Q-43-41231110

Phosphates remain outside the natural cycle for a long time

(A)Whentheyformcompoundswithmetals

(B)Whentheyareincorporatedinbonesandteeth

(C)Whenthebodiesoftheorganismsexcreteand

decompose

(D)Both(1)and(2)

CORRECTANSWER:D

× 100

WatchVideoSolutionOnDoubtnutApp

Q-44-14538183

Percentage of photosyntetically active radiation (PAR) that is

captured by plants in synthesis of organic matter is

(A)50-70%

(B)30-40%

(C)80-100%

(D)2-10%

CORRECTANSWER:D

SOLUTION:

About1-5%ofincidentsolarenergyor2-10%ofPARis

capturedbythephotosyntheticorganismsforthe

synthesisoforganicmatter(Grossprimaryproductivity).

Roughly20%ofitisconsumedinrespirationsothatnet

captureofenergy(netprimaryproductivity)is0.8-4%of

incidentradiationor1.6-8%ofPAR.

WatchVideoSolutionOnDoubtnutApp

Q-45-14538182

Percentage of photosynthetically active radiation (PAR) in the

incident solar radiation is

(A)1-5%

(B)2-10%

(C)lessthan50%

(D)approx100%

CORRECTANSWER:C

SOLUTION:

Lessthat50%ofthesolarenergyincidentoverearthis

PAR(photosyntheticallyactiveradiation).

WatchVideoSolutionOnDoubtnutApp

Q-46-41231257

Which of the following is correctly matched?

(A)Partheniumhysterophorus-Threattobiodiversity

(B)Stratification-Population

(C)Aerenchyma-Opuntia

(D)Agepyramid-Biome

CORRECTANSWER:A

WatchVideoSolutionOnDoubtnutApp

Q-47-55657890

All are true for ''Climax community'' except

(A)Rapidlykeepsonchangingtoreachequilibrium

(B)Finalcommunity

(C)Endofsuccession

(D)Stable

CORRECTANSWER:A

SOLUTION:

Climaxcommunityisstableandisinequilibriumwiththe

environment.

WatchVideoSolutionOnDoubtnutApp

Q-48-14538180

Decomposers are also called as

(A)transducers

(B)reducers

(C)micro-consumers

(D)bothbandc

CORRECTANSWER:D

SOLUTION:

Decomposersarealsocalledasreducersbecausethey

areabletoremoveordegradethedeadbodiesof

organismsandduetotheirsmallsizetheyareknowas

microconsumers.

WatchVideoSolutionOnDoubtnutApp

Q-49-41231236

Pheretima and its close relatives derive nourishment from

(A)Soilinsects

(B)Smallpiecesoffreshfallenleavesofmaize,etc

(C)Sugarcaneroots

(D)Decayingfallenleavesandsoilorganicmatter

CORRECTANSWER:D

WatchVideoSolutionOnDoubtnutApp

Q-50-14538281

Succession in a forest ecosystem is characterised by chnages in

species diversity , biomass and net primary productivity as shwon in

the graph below, identify curves A,B and C.

(A)A:biomassB:netprimaryproductivityC:species

diversity

(B)A:speciesdiversityB:netprimaryproductivityC:

biomass

(C)A:netprimaryproductivityB:biomassC:species

diversity

(D)A:netprimaryproductivityB:speciesdiversityC:

biomass

CORRECTANSWER:D

SOLUTION:

Bioticorecologicalsuccessionisthenatural

developmentofaseriesofbioticcommunitiesatthe

same,site,oneaftertheothertillaclimaxcommunity

developswhichdoesnotchangefurtherbecauseitisin

perfectharmonywiththeenvironmentofthearea.The

changeisorderlyandsequential.Attheendofbiotic

succession,i.e.,whenclimaxcommunityhasformed,

thebiomasshasreachedtothehighestofallbiotic

stages,diversityhasgrownhighernichesaremanyand

specialised.Howeverproductivityhasdecreasedas

respiratoryconsumptionhasincreasedintheclimax

community.

WatchVideoSolutionOnDoubtnutApp

Q-51-41231259

Which of the following National Parks is home to the famous musk

deer or hangul

(A)EaglenestWildlifeSanctuay,ArunachalPradesh

(B)DachigamNationalPark,Jammu&Kashmir

(C)KeibulLamjaoNationalPark,Manipur

(D)BandhagarhNationalPark,MadhyaPradesh

CORRECTANSWER:B

WatchVideoSolutionOnDoubtnutApp

Q-52-41231111

Human dominated environment is called

(A)Biosphere

(B)Noosphere

(C)Socio-culturalenvironment

(D)Noneofthese

CORRECTANSWER:B

WatchVideoSolutionOnDoubtnutApp

Q-53-14538225

The stable community during an acological succession that would

be near equilibrium with the enviorment is called

(A)climaxcommunity

(B)pioneercommunity

(C)sere

(D)carnbivores.

CORRECTANSWER:A

SOLUTION:

Thecommunitythatisinnearequilibriumwiththe

environmentiscalledaclimaxcommunity.

WatchVideoSolutionOnDoubtnutApp

Q-54-41231205

Which one of the following pairs is mismatched.?

(A)Savanna-Acaciatrees

(B)Coniferousforest-Evergreentrees

(C)Tundra-Permafrost

(D)Prairies-Epiphytes

CORRECTANSWER:D

WatchVideoSolutionOnDoubtnutApp

Q-55-41231081

The amount of biogenetic nutrients present in the abiotic

environment per unit area at any time is called.

(A)Standingstate

(B)Standingcrop

(C)NPP

(D)Nutrientsimmobilization

CORRECTANSWER:A

WatchVideoSolutionOnDoubtnutApp

Q-56-14538190

Select the incorrect food chain

(A)Grass Grasshopper Frog Snake

Eagle

(B)Phytoplanktons Zooplanktons smallfish

Largefish

(C)Diatoms Zooplanktons Smallfish

(D)Grass Frog Vulture

CORRECTANSWER:D

SOLUTION:

Frogisthesecondaryconsumer,i.e.,itfeedsupon

herbivoreinaparticularfoodchainbutinthegivenfood

chain(optiond)itisactingasaprimaryconsumer

hence,thegivenfoodchainisincorrect.1

→ → → →

→ →

→

→ →

→ →

WatchVideoSolutionOnDoubtnutApp

Q-57-41231153

Tropical dense forests are due to

(A)Lowrainfallandlowtemperature

(B)Highrainfallandlowtemperature

(C)Lowrainfallandhightemperature

(D)Highrainfallandhightemperature

CORRECTANSWER:D

WatchVideoSolutionOnDoubtnutApp

Q-58-14538307

The zone at the edge of a lake or ocean which is alternatively

exposed to air and immersed in water is called.

(A)pelagiczone

(B)benthiczone

(C)lenticzone

(D)littoralzone.

CORRECTANSWER:D

SOLUTION:

Littoralzoneistheshallowcoastalzone.Lightis

avialableuptobottominthiszone.Therefore,producers

arefoundthroughoutfromsurfacetobottominthiszone.

Rootedvegetationoccursalongshores.Consumersare

alsoavailablethroughout,i.e.,fromsurfacetothe

bottominthiszone.

WatchVideoSolutionOnDoubtnutApp

Q-59-41231165

Which biotic components mainly help in recycling of minerals:-

(A)Producers

(B)Consumers

(C)Decomposers

(D)Alltheabove

CORRECTANSWER:C

WatchVideoSolutionOnDoubtnutApp

Q-60-14538212

Organisms which are associated with first as well as third trophic

level are

(A)macrophytes

(B)Phytoplanktons Zooplanktons smallfish

Largefish

(C)chemoautotrophs

(D)insectivorousplants

CORRECTANSWER:D

SOLUTION:

Trophiclevelisafunctionallevel.Asinglespeciesmay

occupymorethanonetrophiclevel.Insectivorousplants

areproducers,occupyingfirsttrophiclevel.Theyalso

eatinsectsandthus,occupythirdtrophiclevelalso.

WatchVideoSolutionOnDoubtnutApp

Q-61-55657851

→ →

→

Climax communities

(A)Areshortlivedthanpioneercommunities

(B)Arelessstablethanpioneercommunication

(C)Havesimplefoodchainsthanpioneercommunities

(D)Havegreaterniche,specializationthanpioneer

communities

CORRECTANSWER:D

WatchVideoSolutionOnDoubtnutApp

Q-62-41231167

Hydrological cycle is controlled by

(A)Grasslands

(B)Forests

(C)Planktons

(D)Epiphytes

CORRECTANSWER:B

WatchVideoSolutionOnDoubtnutApp

Q-63-14538298

During the process of ecological succession, the changes that take

place in communities are

(A)orderlyandsequential

(B)random

(C)veryquick

(D)notinfluencedbythephysicalenviroment.

CORRECTANSWER:A

SOLUTION:

Bioticorecologicalsuccessionisthenatural

developmentofaseriesofbioticcommunitiesatthe

samesite,oneaftertheothertillaclimaxcommunity

developswhichdoesnotchangefurtherbecauseitisin

perfectharmonywiththeenviroonmentofthearea.The

changeisorderlyandsequential.Thefirstbiotic

communitywhichdevelopsinabareareaiscalled

pioneercommunitywhichdevelopsinabareareais

calledpioneercommunityisastable,selfperpetuating

andfinalbioticcommunity.Itdevelopsattheendof

bioticsuccessionandisincompleteequilibriumwiththe

prevailingenvironment.Theestablishmentofclimax

stageiscalledstabilisation.

WatchVideoSolutionOnDoubtnutApp

Q-64-41231144

Pyramids of biomass in pond ecosystem are

(A)Inverted

(B)Upright

(C)Linear

(D)Irregular

CORRECTANSWER:A

WatchVideoSolutionOnDoubtnutApp

Q-65-41231116

The terminal stage of a successional process is called

(A)Finalstage

(B)Climaxstage

(C)Seralstage

(D)Pioneerstage

CORRECTANSWER:B

WatchVideoSolutionOnDoubtnutApp

Q-66-14538261

The function of reservoir pool is to meet with the deficit of nutrient

that occurs due to

(A)imbalanceinrateofeffluxandinfluxofnutrients.

(B)onlyeffluxofnutrients

(C)ceasednutrientcycle

(D)Noneofthese

CORRECTANSWER:A

WatchVideoSolutionOnDoubtnutApp

Q-67-55657886

In a terrestrial ecosystem the large fraction of energy flows through

(A)detritusfoodchain

(B)grazingfoodchain

(C)herbivores

(D)carnivores

CORRECTANSWER:A

SOLUTION:

InanaquaticecosystemGFCisthemajorconduitfor

energyflow,whereasinaterrestrialecosystemitis

throughtheDFC.

WatchVideoSolutionOnDoubtnutApp

Q-68-41231141

In a food chain, the total amount of living material is depicted by:

(A)Pyramidofbiomass

(B)Pyramidofenergy

(C)Pyramidofnumber

(D)Trophiclevels

CORRECTANSWER:A

WatchVideoSolutionOnDoubtnutApp

Q-69-14538241

Correct sequence of stages of succession of a lithosere is

(A)Folioselichens Crustoselichens Mosses

Annualgrasses Perennialgrasses

Shrubs Trees.

(B)Crustoselichens Folioselichens Mosses

Perennialgrasses Annualgrasses

Annulagrasses Shrusb Trees

(C)Reedswampstage Sedges Floatingplants

Submergedplants

(D)Sedges Reedswampstage Floatingplants

Submergedplants

CORRECTANSWER:C

WatchVideoSolutionOnDoubtnutApp

Q-70-55657885

→ →

→ → →

→

→ →

→ → →

→ →

→ →

→

→ →

→

Sun is the only source of energy for the given ecosystems except

(A)deepseahydrothermalecosystem

(B)savannahecosystem

(C)shallowlakeecosystem

(D)mangroveecosystem

CORRECTANSWER:A

WatchVideoSolutionOnDoubtnutApp

Q-71-41231160

The concept of ecological pyramid was given by

(A)Odum

(B)Elton

(C)Darwin

(D)Reiter

CORRECTANSWER:B

WatchVideoSolutionOnDoubtnutApp

Q-72-14538308

Edaphic factor refers to

(A)Water

(B)soil

(C)relativehumidity

(D)altitude

CORRECTANSWER:B

SOLUTION:

Edaphicfactorsareclassifiedundertheabioticfactors

affectinganecosystem.Edaphicfactorsincludefactors

ofsoil,e.g.,soiltexture,substratum,topography,mineral

composition,pH,etc.Thesefactorscaninfluencethe

distributionandinterrelationshipsoforganisms,aswell

asrateofdecomposition.

WatchVideoSolutionOnDoubtnutApp

Q-73-55657875

How much of the net primary productivity of a terrestrial ecosystem

is eaten and digested by herbivores?

(A)

(B)

(C)

(D)

1 %

10 %

40 %

90 %

CORRECTANSWER:B

WatchVideoSolutionOnDoubtnutApp

Q-74-41231168

Savannahs are

(A)Tropicalrainforest

(B)Desert

(C)Grasslandwithscatteredtrees

(D)Denseforestwithclosecanopy

CORRECTANSWER:C

WatchVideoSolutionOnDoubtnutApp

Q-75-14538271

Major source of sulphur is

(A)oceans

(B)land

(C)rocks

(D)lakes.

CORRECTANSWER:C

SOLUTION:

Sulpheroccursinnatureasanelementandalsoas

sulphatesinsoil,waterandrocks.Majorreservoirof

sulphurissulphaterocks.Soilandwateralsoreceive

sulphatesfromrocks.Rainwaterrunningoverrocks

graduallywearsawaytheirsurfaceandcarriesoff

sulphurwithit.Someofthissulphursoaksintothesoil

andsomereachespondsandlakes.Alargepartof

sulphuriscarriedbytheriverstotheseawhereitmay

getlockedupinsedimentaryrocks.Windmayalso

erodetherocks,andthematerialsmaybeblownintothe

airasdust.Rainwashesasignificantamountofthis

matterfromtheatmosphereintotheoceans.

WatchVideoSolutionOnDoubtnutApp

Q-76-41231185

In India, temperate evergreen vegetation occurs mostly in

(A)WesternHimalayasabove3500m

(B)EasternandWesternHimalayaslessthan3500m

(C)RajasthanandSouthPunjab

(D)WesternGhatsandAssam

CORRECTANSWER:B

WatchVideoSolutionOnDoubtnutApp

Q-77-55657872

The process of mineralisation by micro organisms helps in the

release of

(A)inorganicnutrientsfromhumus

(B)bothorganicandinorganicnutrientsfromdetritus

(C)organicnutrientsfromhumus

(D)inorganicnutrientsfromdetritusandformationof

humus

CORRECTANSWER:A

WatchVideoSolutionOnDoubtnutApp

Q-78-14538275

Which of the following is most important in water cycle?

(A)Transpirationthroughleaves

(B)Evaporationfromtheoceans

(C)Percolationofwaterintotheground

(D)Absorptionofcapillarywaterbyplants

CORRECTANSWER:B

SOLUTION:

Evaporationfromtheoceansisthemostimportanin

watercycle,becauseitcomprisesofthemajorpartof

globalwatercycle.

WatchVideoSolutionOnDoubtnutApp

Q-79-41231229

In an area where DDT had been used extensively, the population of

birds declined significantly because:

(A)Earthwormsintheareagoteradicated

(B)Crobeswerefeedingexclusivelyonbirds

(C)Manyeggslaidbybirdsdidnothatch

(D)Birdsstoppedlayingeggs

CORRECTANSWER:C

WatchVideoSolutionOnDoubtnutApp

Q-80-14538286

Decomposers like fungi and bacteria are

(A)autotrophs

(B)heterotrophs

(C)saprotrophs

(D)chemo-autotrophs.

CORRECTANSWER:C

SOLUTION:

Decomposerslikebacteriaandfungiareheterotrophs

becausetheyaredependentonothersfortheirfoodas

theycannotmaketheirownfood.Theyarealso

sarprotrophsbecausetheyfeedondeadanddecaying

organicmatter.

WatchVideoSolutionOnDoubtnutApp