CO C · 2020. 1. 7. · PHOTOSYNTHESIS IN HIGHER PLANTS Revise Most Important Questions to Crack NEET 2020 Download Doubtnut Now Q-1 - 46831993 Phosphoenol pyruvate (PEP) is the primary

NEETREVISIONSERIES

PHOTOSYNTHESISINHIGHERPLANTS

ReviseMostImportantQuestionstoCrackNEET2020

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Q-1-46831993

Phosphoenol pyruvate (PEP) is the primary acceptor in

(A) -plants

(B) -plants

(C) -plants

(D) -plants

CORRECTANSWER:B

SOLUTION:

PhospheonolPyruvate(PEP)isfoundinthemesophyll

cell,whichacceptstheatmospheric in -plants

CO2

C3

C4

C2

C3 and C4

CO2 C4

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andconvertsittooxaloacetate-a compound.Itis

thefirststablecompoundof -plants

ConceptEnchancer -plantspossessspecial

adaptationanatomyintheirleavestocopeupthe

photorespiratorylosses.Therearedimorphicchloroplast

presentinthem-agranalinbundlesheathcellsand

granalinmesophyllcells.

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Q-2-46831998

In a chloroplast the highest number of protons are found in

(A)lumenofthylokoids

(B)intermembranespace

(C)antennaecomplex

(D)stroma

C4

C4

C4

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CORRECTANSWER:A

SOLUTION:

Protonconcentrationishigherinthelumenofthylokoid

duetophotolysisofwater, pumpingadNADP

reductaseactivitywhichoccursinstromaofthe

chloroplast.


Q-3-46832000

The process which makes major difference between

plants is:-

(A)glycolysis

(B)Calvincycle

(C)Photorespiration

H +

C3 and C4

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(D)respiration

CORRECTANSWER:C

SOLUTION:

Photorespirationistheprocesswhichmakesa

differencebetweenthe -plants.Inthis

process,thereisacontinuouslossofcarbonfixedinthe

formof .

Itoccursduetothehigh content,hightemperature

conditionsinwhichRuBPcarboxylasestartsworkingas

RuBPoxygenateandnormalphotosynthesisdoesnot

occur.

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Q-4-46832004

The correct sequence of cell organelles during photores piration is

C3 and C4

CO2

O2

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(A)Cloroplast-Golgibodies-mitochondria

(B)chloroplast-roughendoplasmicreticulum-

dictyosomes

(C)chloroplast-mitochondria-peroxisome

(D)chloroplast-vacuole-peroxisome

CORRECTANSWER:C

SOLUTION:

Noneoftheoptioniscorrec.Photorespirationrequired

threecellorganellesinsequenceofchloroplast,

peroxisomeandmitochondria.Option(c)maybecorrect

ifbereadassaidsequence.


Q-5-46832007

https://doubtnut.app.link/fNugBUwIW2https://doubtnut.app.link/FOFKgXwIW2

PGA as the first fixation product was discovered in

photosynthesis of

(A)bryophyte

(B)gymnosperm

(C)angiosperm

(D)alga

CORRECTANSWER:D

SOLUTION:

Theuseofradiactive byMelvincalvininalgal

(chlorella)photosynthesisstudiesledtothediscovery

thatthefist fixationproductwasa3-carbonorganic

acid.Thefirstproductidentifiedwas-phosphoglyceric

acid(PGA).

CO2

.14 C

CO2

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Q-6-46832013

In the leaves of -plants, malic acid formation during -

fixatino occurs in

(A)mesophyll

(B)bundlesheath

(C)phloem

(D)epidermis

CORRECTANSWER:A

SOLUTION:

Theoxalicacidisreducedtomalicacidinmesophyll

cells,fromchloroplastofmesophyllcellsthemalicacid

istransferredtothechloroplastofbundlesheathcells

C4 CO2

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where,itisdecarboxylatedtoform andpyruvic

acid.


Q-7-46832017

As compared to a plant, how many additional molecules of ATP

are needed for net production of one molecule hexose sugar by

plants

(A)2

(B)6

(C)12

(D)zero

CORRECTANSWER:C

SOLUTION:

CO2

C3

C4

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In -plantsevery moleculeastobefixedtwice,

sotheseplantsareneededmoreenergyfor -plantsin

which hastobefixedonlyonce.18ATPmolecules

arerequiredby -plantsforthesynthesisofone

moleculeofhyexosesugarwhile30ATPmoleculesare

neededbythe -plantsforthesame.thus, -plants

haveaneedof12ATPmoleculesextrathan -plants

forthesynthesisofonemoleculeofhexosesugar.


Q-8-46832022

In chloroplasts, chlorophyll is presents in the

(A)outermembrane

(B)innermembrane

(C)thylakoids

C4 CO2

C3

CO2

C3

C4 C4

C3

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(D)stroma

CORRECTANSWER:C

SOLUTION:

Thethylakoidsofchloroplastareflattenedvesicles

arrangedasamembranousnetworkwithinthestroma.

50%ofchloroplastproteinsandvariouscomponents

involved(namelychlorophyll,carotenoidsand

plastoquinone)inphotosynthesisarepresentinthylakoid

membranes.


Q-9-46832025

Which one of the following is wrong in relation to photorespiration

(A)itisacharacteristicof -plantsC3

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(B)itoccursinchloroplasts

(C)Itoccursindaytimeonly

(D)itisacharacteristicof -plants

CORRECTANSWER:D

SOLUTION:

DickerandTio(1959)discoveredphotorespirationin

tobaccoplant.Itisalightdepedentprocessof

oxygenationofRibuloseBisphoshate(RuBP).During

thisprocess isliberatedand isconsumed. -

plantsavoidphotorespirationbyfollowinghatchslack

pathway.


Q-10-46832001

C4

CO2 O2 C4

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In photosynthesis, light independent reactions take place at

(A)thylakoidlumen

(B)photosystem-I

(C)photosystem-II

(D)stromalmatrix

CORRECTANSWER:D

SOLUTION:

Thelight-independentreactions(ordarkreactions)take

placeinthestromalmatrixofthechloroplasts.Inlight

independentreactions,carbondioxideisreducedto

glucose(carbohydrate)bythehydrogeninNADPHby

usingthechemicalenergystoredinATP.Thisreaction

takesplaceinthepresenceofasubstancecalledRuDP.

https://doubtnut.app.link/WVhI38wIW2


Q-11-46832031

how many turns of Calvin cycle yield one molecule of glucose?

(A)8

(B)2

(C)6

(D)4

CORRECTANSWER:C

SOLUTION:

Conversionof tosimple(reduced)organic

compoundsiscalled assimilationor fixation

orcarbonfixation.Thisfixationpathwaywaselucidated

intheearly1950sbyMelvincalvinandCoworkensand

CO2

CO2 CO2

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isoftencalledascalvincycle.Since,onemoleculeof

carbonisfixedinoneturnofthecalvincycle.so,six

turnsofthecyclearerequiredtofixtheglucose

moleculescontaining6carbonatoms.


Q-12-46832038

Protochlorophyll differs from chlorophyll in lacking

(A)2hydrogenatomsintwoofitspyrrolerings

(B)2hydrogenatomsintwoofitspyrrolerings

(C)4hydrogenatomsinoneofitspyrrolerings

(D)4hydrogenatomsintwoofitspyrrolerings

CORRECTANSWER:A

SOLUTION:

https://doubtnut.app.link/XvABGbxIW2https://doubtnut.app.link/YEsWhdxIW2

Protochlorophylldiffersfromchlorophyllinlacking2

hydrogenatomsinoneofitspyrrolerings.


Q-13-46832041

Which of the following is present in Calvin Cycle.

(A)Reductivecarboxylation

(B)Oxidativecarboxylation

(C)Photophosphorylation

(D)Oxidativephosphorylation

CORRECTANSWER:A

SOLUTION:

IndarkphaseorCalvincycle,carbondioxideis

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assimilatedwiththehelpofassimilatorypower(ATPand

)toproduceorganicacid.Thecycleinvolves

reductionofcarboninvolvingcarboxylation,glycolytic

reversalandregenerationofRuBP. cycleisalso

knownasreductivepentosepathwayorphotosynthetic

carbonReduction(PCR).


Q-14-46832047

Which one occurs both during cyclic and non-cyclic modes of

photophosphorylation

(A)involvementofbothPS-IandPS-II

(B)formationofATP

(C)Releaseof

(D)FormationofNADPH

NADPH2

C3

O2

https://doubtnut.app.link/e8f2bfxIW2https://doubtnut.app.link/dPhEQhxIW2

CORRECTANSWER:B

SOLUTION:

Cyclicphotophosphorylationisthattypeoflight

energisedATPsynthesisinwhichelectronexpelledby

excitedphotocentredoesnotreturntothem.Itinvolves

twophotochemicalsystems(PS-IandPS-II)and

producesassimilatorypower(ATPandNADPH).Inboth,

cyclicandnon-cyclicphotophoshorylation,formationof

ATPtakesplace.


Q-15-46832057

The enzyme that catalyses carbon dioxide fixation in plants is

(A)RuBPcarboxylase

C4

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(B)PEPcarboxylase

(C)carbonicanhydrase

(D)carboxydismutase

CORRECTANSWER:B

SOLUTION:

In -plants,mesophyllcellsfixcarbondioxidewiththe

helpofphosphoenol-pyruvate(thefirstacceptor)inthe

presenceofPEPcarboxylasetoacompound

oxaloaceticacid(firstproduct).


Q-16-46832064

Ferredoxin is a constituent of

(A)PS-I

C4

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(B)PS-II

(C)Hillreaction

(D)

CORRECTANSWER:A

SOLUTION:

Ferrodoxin(Fd)isasolubleproteinwhichactsas

electroncarrierandformsaconstituentofPS-I

ferredoxinpasseselectronstoreductasecomplexwhich

helpsinreducing toNADPH(astrong

reducingagent).


Q-17-46832071

The substrate for photorespiration is

P680

NADP +

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(A)phosphoglycericacid

(B)glycolate

(C)serine

(D)glycine

CORRECTANSWER:B

SOLUTION:

Photorespirationistheoxidationofphotosynthetic

intermediatewithoutproductionofphotosynthetic

intermediatewithoutproductionof .ATPand

.Thesubstrateforphotorespirationisa2-

carboncompoundglycolicacid(glycolate).


Q-18-36805993

CO2

NADH2

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Which of the following is not a product of light reaction of

phtosynthesis

(A)NADPH

(B)NADH

(C)ATP

(D)Oxygen

SOLUTION:

DuringlightreactionofphotosynthesisNADPH,ATP

andoxygenareformed.Oxygenisliberatedbythe

photolysisofwater.

4H2O ⇔ 4H +

+ 4OH −

https://doubtnut.app.link/Sn4mtrxIW2


Q-19-26295544

Which metal ion is a constituent of chlorophyll?

(A)Iron

(B)Copper

(C)Magnesium

(D)Zinc

CORRECTANSWER:C

SOLUTION:

4OH −

Oxygen-Evolvingcomplex−−−−−−−−−−−−−−−−→

Mn2+ ,Ca2+ ,Cl−2H2O

+ O2↑⏐⏐⏐⏐

+ 4e−

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(c)Magnesium(Mg)ispresentinthecentreofporphyrin

ringofthechlorophyllmolecule.Otherions,i.e.,copper

andzincparticipateinothermetabollicprocesseswhich

are

Feisanimportantpartofcytochromeandferridoxin.

Cuplaysanimportantroleinenzymecatalysingredox

reactions.

Znisassociatedwithauxin(aphytohormone)

synthesis.


Q-20-30688775

17.0 / if one hundred M The sum of the parallelograms of the stripes

is 5.5 ... S respectively, with a center on the first (Common

Difference) Probably 1,23 ... m, so prove that 5 52 + ... + s .-- (m +

10 (E-1) Omnipresent 5 yes yes sister key

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Q-21-30698770

Of the total incident solar radiation the proportion of PAR is:

(A)Lessthan50%

(B)Morethan80%

(C)About70%

(D)About60%.

CORRECTANSWER:A


Q-22-46832075

Carbon dioxide joins the photosynthetic pathway in

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(A)PS-I

(B)PS-II

(C)lightreaction

(D)darkreaction

CORRECTANSWER:D

SOLUTION:

Indarkreactionofphotosynthesis,reducingagent

(NADPH)andsourceofenergy(ATP)formedduring

lighhtreaction,areutilisedintheconversionof to

carbohydrates.


Q-23-46832018

Photosynthesis in plants is relatively less limited by atmospheric

CO2

C4

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levels because

(A)effectvepumpingof intobundlesheathcells

(B)RuBisCOin -plantshashigheraffinityfor

(C)Fourcarbonacidsaretheprimaryinitial -

fixationproducts

(D)Theprimaryfixationof ismediatedviaPEP

carboxylase

CORRECTANSWER:D

SOLUTION:

Thefixationof in -plantstakesplaceintwo

placesandbytwodifferentorganiccompounds.

Phosphoenolpyruvate(PEP)isfoundatmospheric

intooxaloaceticacid(4C).RuBisCOispresentinbundle

sheathcellswherefinalfixationof inhexose

CO2

CO2

C4 CO2

CO2

CO2

CO2 C4

CO2

CO2

https://doubtnut.app.link/YTbcAAxIW2

sugarstakesplace. isprimarilyfixedbyPEP

carboxylasebecausethisenzymehasgreateraffinityto

thanRuBisCO.


Q-24-46832053

Formation of ATP in photosynthesis and respiration in an oxidation

process which utilises the energy from:-

(A)cytochromes

(B)ferredoxin

(C)electrons

(D)carbondioxide

CORRECTANSWER:C

SOLUTION:

CO2

CO2

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Cytochromes(Keilin,1925)aretheelectrontransport

intermediatescontainingheme(orrelatedprosthetic

groups)inwhichtheironundergoesvalanceychanges

duringelectrontransferandproducesenergy(ATP)in

bothphotosynthesisandrespiration.


Q-25-46832065

During monsoon, the rice crop of eastern states of India shows

lesser yield due to limiting factor of

(A)

(B)light

(C)temperature

(D)water

CO2

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CORRECTANSWER:B

SOLUTION:

Accordingtotheprincipleoflimitingfactor,therateof

theprocessislimitedbythepaceoftheslowestfactor.

Lightintensityvarieswithlatitude,altitude,season,

topography,presenceorabsenceofinterceptorslike

cloud,dust,fog,humidity,etc.Ineasternstates,lowlight

intensityduringmonsoonresultinlowphotosynthesis

andhence,lesseryield.


Q-26-46832070

In plants, Calvin cycle operates in

(A)stromaofbundlesheathchloroplasts

C4

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(B)granaofbundlesheathchloroplasts

(C)granaofmesophyllchloroplasts

(D)stromaofmesophyllchloroplats

CORRECTANSWER:A

SOLUTION:

-plantspossesstwotypesofchloroplastsgranalin

mesophyllcellsandagrenalinbundlesheathcells.

Mesophyllcellsarespecialisedtoperformlightreaction

andbundlesheathcellspossess

CO_(2)`isfixedthroughcalvincycle.


Q-27-30698772

In kranz anatomy, the bundle sheath cells have

C4

RuBisCO, here

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(A)Thickwalls,manyintercellularspacesandno

chloroplasts

(B)Thinwalls,nointercellularspacesandlargenumber

ofchloroplasts

(C)Thickwalls,nointercellularspacesandfew

chloroplasts

(D)Thinwalls,manyintercellularspacesandseveral

chloroplasts.

CORRECTANSWER:B


Q-28-30698765

Optimum temperature for photosynthesis is

(A)35 ∘ − 40 ∘C

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(B)

(C)

(D) .

CORRECTANSWER:C


Q-29-30698763

Formation of phosphoglyceraldehyde from phosphoglyceric acid is

(A)Hydrolysis

(B)Oxidation

(C)Reduction

(D)Electrolysis.

CORRECTANSWER:C

25 ∘ − 35 ∘C

20 ∘ − 25 ∘ C

10 ∘ − 15 ∘ C

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Q-30-30698755

Plants requiring low light intensity for optimum photosynthesis is

called:

(A)Bryophytes

(B)Pteridophytes

(C)Heliophytes

(D)Sciophytes.

CORRECTANSWER:D


Q-31-30698752

In three Calvin cycles, gross number of PGAL molecules produced

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at the cost of ATP and

(A)

(B)

(C)

(D)

.

CORRECTANSWER:B


Q-32-30698758

NADPH2

3P GAL, 3AT P ,3NADPH2

6P GAL, 6AT P ,6NADPH2

18PGAL, 18AT P ,18NADPH2

9P GA, 9ATP ,9NADPH2

https://doubtnut.app.link/ukleIQxIW2https://doubtnut.app.link/kKjcxSxIW2

RuBisCo occurs in high quantity as it is

(A)Anoxygenase

(B)Catalysingreversiblereaction

(C)Degradedrapidly

(D)Veryslowactingenzyme.

CORRECTANSWER:D


Q-33-46832020

In plants, the first stable product of photosynthesis during dark

reaction is

(A)Malicacid

(B)oxaloaceticacid

C3

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(C)3phosphoglycericacid

(D)phosphoglyceraldehyde

CORRECTANSWER:C

SOLUTION:

In -plantsthefirststableproductformedduringdark

reactionis3-phosphoglycericacid.Since,itisa3carbon

compoundhence,thepathwayisreferredas -

pathway.OxaloaceticAcid(OAA)isthefirststable

compoundin -plants.itisa4Ccompound.


Q-34-30698764

Rate of photosynthesis is maximum in

(A)Orangelight

C3

C3

C4

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(B)Yellowlight

(C)Bluelight

(D)Greenlight.

CORRECTANSWER:C


Q-35-30698762

Electron energy is used to drive protons against concentration

gradient across thylakoid membrane into

(A)Stromalamella

(B)Thylakoidlumen

(C)Stroma

(D)Interthylakoidspace.

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CORRECTANSWER:B


Q-36-46832076

is reduced to NADPH in

(A)PS-I

(B)PS-II

(C)Calvincycle

(D)Non-cyclicphotophosphorylation

CORRECTANSWER:D

SOLUTION:

Inphotosynthesisduringnon-cyclicphotophoshorylation

involvingbothPS-IandPS-II,electronsreleasedduring

NADP +

https://doubtnut.app.link/mxjy1ZxIW2https://doubtnut.app.link/WkyF22xIW2

photolysisofwateraretransferredtoPS-IIandthenPS-I

viaaseriesofelectroncarriers. ofPS-Ireleases

electronafterabsorbinglightenergyThiselectron

passesthroughchlorophyllX,Fe-S,ferredoxinand

finallyto combineswith

(releasedduringphotolysis)withthehelpofNADP

reductasetoformNADPH.


Q-37-46832054

Translocation of carbohydrate nutrients usually occurs in the form

of

(A)glucose

P700

NADP + . NADP + H +

NADP + + 2e−

+ H +

NADPreductase−−−−−−−−−→ NADP H

https://doubtnut.app.link/WkyF22xIW2https://doubtnut.app.link/ZGdgN5xIW2

(B)maltose

(C)starch

(D)sucrose

CORRECTANSWER:D

SOLUTION:

Inplants,translocation,i.e.themovementoforganic

nutrientsfromtheregionofsupplytotheregionofsink

orutilisationoccursthroughphloem(sievetube/sieve

cells)tissue.Translocatedorganicnutrientsconstitute

10-26%carbohydrates(usuallysucrose)and1%

nitrogenouscomponents(mostlyaminoacids).


Q-38-46832045

https://doubtnut.app.link/ZGdgN5xIW2https://doubtnut.app.link/Koa5h7xIW2

Pigment acting as a reaction centre during photosynthesis is

(A)carotene

(B)phytochrome

(C)

(D)cytochrome

CORRECTANSWER:C

SOLUTION:

Photosyntheticpigmentmolecule(e.g. )are

abletoconvertlightenergyintochemicalenergy.These

pigmentmoleculeswhichtoetherformsthe

photosyntheticunits,possessphotocentres(reaction

centre=trapcentre)surroundedbyharvestingmolecules

differentiatedintocoremoleculesandantenna

molecules.

P700

P700, P680

https://doubtnut.app.link/Koa5h7xIW2


Q-39-46832029

Which pigment system is inactivated in red drop?

(A)PS-IandPS-II

(B)PS-I

(C)PS-II

(D)Noneoftheabove

CORRECTANSWER:C

SOLUTION:

Thefallinphotosyntheticyieldbeyondredregionof

spectrum(680nm)iscalledreddrop.Reactioncentreof

PS-IIis whilethatofPS-Iis .SointheredP680 P700

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dropreactionPS-IIisinactivated.


Q-40-46831994

With reference to factors affecting the rate of photosynthesis, which

of the following statements is not correct ?

(A)Lightsaturationfor -fixationoccursat10%offull

sunlight

(B)increasingatmospheric concentrationupto

0.05%canenchance -fixationrate

(C) -plantsrespondtohighertemperaturewith

enchancedphotosynthesis,while -plantshavemuch

lowertemperatureoptimum

(D)Tomatoisgreenhousecrop,whichcanbegrownin

enrichedatmosphereforhigheryield.

CO2

CO2

CO2

C3

C4

CO2

https://doubtnut.app.link/KrYHL8xIW2https://doubtnut.app.link/DQPigayIW2

CORRECTANSWER:C

SOLUTION:

In -plants,theinitialfixationof occursin

mesophyllcells.Theprimaryacceptorof in

phosphoenolPyruvate(PEP).Itcombineswith in

thepresenceofenzymePEPcarboxylasetoformthe

firststableproduct,i.e.OxaloaceticAcid(OAA).Where

as -plantslack enzyme.Thepossess

RuBisCOenzyme.Thisenzymecanworkasboth

carboxylase(fixationof )andoxygenase(fixationof

).RuBisCOhasamuchgreateraffinityfor than

for andthebindingiscompetitive.Athigher

temperature,itsaffinityfor decreaseanditworks

asoxygenase.Therefore,athighertemperature

photosynthesisdecreasein -plants,whilein -plants

itincreases.

C4 CO2

CO2

CO2

C3 PEPcarboxylase

CO2

O2 CO2

O2

CO2

C3 C4

https://doubtnut.app.link/DQPigayIW2


Q-41-46831999

The oxygen evolved during photosynthesis comes from water

molecules . Which one of the following pairs of elemnets is

involved in this reaction ?

(A)Manganeseandchlorine

(B)Manganeseandpotassium

(C)Magnesiumandmolybdenum

(D)Magnesiumandchlorine

CORRECTANSWER:A

SOLUTION:

Photolysisofwaterduringphotosynthesisevolve

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nascentoxygeninthepresenceofmanganese,calcium

andchlorideions.


Q-42-46832002

Anoxygenic photosynthesis is characteristic of

(A)Rhodospirillum

(B)Spirogyra

(C)Chlamydomonas

(D)Ulva

CORRECTANSWER:A

SOLUTION:

Anoxygenicphotosynthesis(inwhich isnotreleased)O2

https://doubtnut.app.link/YDCrwyYIW2https://doubtnut.app.link/ye7ZzBYIW2

isseeninRrhodospirilllumwhichisapurplenon-sulphur

bacteria.Ithelpsanorganismtotraplightenergyand

storeitaschemicalenergy.Otherthanthisanoxygenic

photosynthesiscommonlyoccursinpurplenon-sulphur

bacteriagreensulphur/non-sulphurbacteria,and

heliobacteria,etc.


Q-43-46832006

Of the total incident solar radiation the proportion of PAR is:

(A)about60%

(B)lessthan50%

(C)morethan80%

(D)about70%

https://doubtnut.app.link/ye7ZzBYIW2https://doubtnut.app.link/GHJ0nEYIW2

CORRECTANSWER:B

SOLUTION:

PAR(photosyntheticallyactiveradiation)designatesthe

spectralrangeofsolarradiationfrom400-700nmthat

photosyntheticorganismsareabletouseintheprocess

ofphotosynthesis.Ofthetotalincidentsolarradiationthe

proportionofPARislessthan50%.


Q-44-46832015

In photosystem-I the first electron acceptor is

(A)cytochrome

(B)plastocyanin

(C)aniron-sulphurprotein

https://doubtnut.app.link/GHJ0nEYIW2https://doubtnut.app.link/rUYHbHYIW2

(D)ferredoxin

CORRECTANSWER:C

SOLUTION:

Inphotosystem-I,theprimaryelectronacceptoris

probableaFe-Sprotein.Thereducedprimaryacceptor

transferstheelectronstosecondaryelectronacceptor

(mostprobable ).Thesequenceofelectrontransfer

isasfollows:

Thereduced passessitselectronstoferredoxin

P430

P700( chl −a+ )

e−

−−→ A1(Phyloquinone )

e−

−−→ A2(Fe-Sprotein )

e−

−−→ A3(P430 )

P430

https://doubtnut.app.link/rUYHbHYIW2

(Fd)presentatoutersurfaceofthylakoidmembrane.


Q-45-46832024

In sugarcane plant is fixed in malic acid, in which the

enzyme that fixes is

(A)fuctosephosphatase

(B)ribulosebisphosphatecarboxylase

(C)phosphoenolpyruvicacidcarboxylase

(D)ribulosephosphatekinase

CORRECTANSWER:C

SOLUTION:

In -plants, istakeupbyPhosphoenol-Pyruavate

^ (14)CO2

CO2

C4 CO2

https://doubtnut.app.link/rUYHbHYIW2https://doubtnut.app.link/H1zUYJYIW2

(PEP)andthereactionbeingcatalysedbyPEP

carboxylase.

.


Q-46-46832028

In photosynthesis , energy from light reaction to dark reaction is

transferred in the form of

https://doubtnut.app.link/H1zUYJYIW2https://doubtnut.app.link/eXfxELYIW2

(A)ADP

(B)ATP

(C)RuDP

(D)chlorophyll

CORRECTANSWER:B

SOLUTION:

Asaresultoflightreaction,oxygen,NADPHatATPare

formed.Oxygenisreleasedintotheatmospherewhile

NADPHandATPareutilisedforreductionof to

carbohydrateindarkreaction.


Q-47-46832039

NADPH is generated through

CO2

https://doubtnut.app.link/eXfxELYIW2https://doubtnut.app.link/2U3oKOYIW2

(A)photosystem-I

(B)photosystem-II

(C)anaerobicrespiration

(D)glycolysis

CORRECTANSWER:B

SOLUTION:

NADPHisgeneratedthroughphotosystem-IIinnon-

cyclicphotophosphorylation(whichinvolvesbothPS-I

andII)protonsreleasedfromphotolysisandelectrons

emittedfrom areultimatelypassedonto

resultingintheformationofNADPH.Incyclic

photophosphorylation(whichinvolvesonlyPS-I)

electronsflowinacyclicmannerbutthereisnotnet

formationofNADPHand .

P700 NADP+

O2

https://doubtnut.app.link/2U3oKOYIW2


Q-48-46832043

Chorophyll 'a' molecule at its carbon atom 3 of the pyrrole ring II

has one of the following

(A)aldehydegroup

(B)methylgroup

(C)carboxylgroup

(D)megnesium

CORRECTANSWER:A

SOLUTION:

Chlorophyllhasatetrapyrroleporphyrinheadandalong

chainalcoholcalledphytoltail.Eachpyrroleisa5

memberringwithonenitrogenandfourcarbon.Anon-

https://doubtnut.app.link/2U3oKOYIW2https://doubtnut.app.link/vIwWgQYIW2

ionicMgatomliesinthecentreofporphyrin,attachedto

nitrogenatomsofpyrrolerings.Chlorophyll-ahasmethyl

groupascarbon3ofpyrroleringandchlorophyll-bhas

foormyl(aldehyde)groupattachedtothisatom.


Q-49-46832049

A photosynthesising plant is releasing more than the normal.

The plant must have been supplied with

(A)

(B) with

(C) with

(D) with

CORRECTANSWER:B

.18 O

O3

H2O .18 O

CO2 .18 O

C6H12O6 .18 O

https://doubtnut.app.link/vIwWgQYIW2https://doubtnut.app.link/vZyZJRYIW2

SOLUTION:

Ruben,HassidandKamen(1941)usingheavyisotope

ofoxygen, inwater,foundthatoxygenevolvedin

photosynthesiscomesfromwaterevolutionofoxygen

doesnotrequirecarbondioxide.


Q-50-46832060

Chlorophyll a occurs in

(A)allphotosyntheticautotrophs

(B)inallhigherplants

(C)alloxygenliberatingautotrophs

(D)allplantsexceptfungi

CORRECTANSWER:B

O18

https://doubtnut.app.link/vZyZJRYIW2https://doubtnut.app.link/tH4kqUYIW2

SOLUTION:

Chlorophyll-a isabluishgreen

pigment,itistheprimaryphotosyntheticpigmentor

universalphotosyntheticpigmentthatoccursinallplants

exceptphotoautotrophicbacteria,i.e.,foundinoxygenic

photoautotrops.


Q-51-46832011

Cyclic-photophosphorylation results in the formation of

(A)NADPH

(B)ATPandNADPH

(C)ATP,NADPHand

(D)ATP

(C55 − H72O5N4Mg)

O2

https://doubtnut.app.link/tH4kqUYIW2https://doubtnut.app.link/R0KGqWYIW2

CORRECTANSWER:D

SOLUTION:

Cyclic-photophosphorylationinvolvesonlypigment

system-IandresultintheformationofATPonly.When

thephotonsactivatePS-I,apairofelectronsareraised

toahigherenergylevel.Theyarecapturedbyprimary

acceptorwhichpassesthemontoferredoxin,

plastoquinone,cytochromecomplex,plastocyninand

finallybacktoreactioncentreofPS-I,i.e., Ateach

stepofelectrontransfer,theelectronslosepotential

energy.theirtripdownhilliscausedbythetransport

chaintopump acrossthethylokoidmembrane.The

protongradientthusestablishedisresponsiblefor

formingATP(2molecules).NoreductionofNADPto

NADPH+


P700

H +

H +

https://doubtnut.app.link/R0KGqWYIW2

Q-52-46832034

Fixation of one molecule through calvin cycle requires

(A)1ATPand2NADP

(B)2ATPand

(C)3ATPand

(D)2ATPand

CORRECTANSWER:C

SOLUTION:

2ATParerequiredduringconversionofPGAto1,3

diphosphoglycericacidand1ATPduringconversionof

glyceraldehydephosphatetoribulosebiphosphate.2

moleculesareutilisedforconverting1,3

diphosphoglycericacidtoglyceraldehydephosphate.

CO2

H2

2NADPH2

2NADPH2

1NADPH2

NADPH2

https://doubtnut.app.link/R0KGqWYIW2https://doubtnut.app.link/LIsezYYIW2


Q-53-46832062

Photosynthetic pigments found in the chloroplasts occur in

(A)thylakoidmembranes

(B)plastoglobules

(C)matrix

(D)chloroplastenvelope

CORRECTANSWER:A

SOLUTION:

Photosyntheticpigmentsarethosepigmentswhich

occuronphotosyntheticthylakoidsofchloroplastand

absorblightenergyforthepurposeofphotosynthesis.

Thesearemainlyoftwotypes-chlorophyllsand

https://doubtnut.app.link/LIsezYYIW2https://doubtnut.app.link/lriZk1YIW2

carotenoids.


Q-54-46832066

Which technique has helped in inverstigation of calvin cycle ?

(A)X-raycrystallography

(B)X-raytechnique

(C)Radioactiveisotopetechnique

(D)Intermittentlight

CORRECTANSWER:C

SOLUTION:

Calvin,bensonandbasshanutilised (withlonglife)

totracethepathofcarboninphotosynthesis.Calvinwas

C 14

https://doubtnut.app.link/lriZk1YIW2https://doubtnut.app.link/nItP02YIW2

awardednobelprizein1961inrecomgnitiontohiswork

with isotope.Hediscoveredthecycleinvolvedin

carbonassimilation,knownascalvincycleor -cycle.


Q-55-46832051

The carbon dioxide acceptor in Calvin cycle/ - plants is

(A)PhosphoenolPyruvate(PEP)

(B)Ribulose1,5-Diphosphate(RuDP)

(C)Phosphoglycericacid(PGA)

(D)Ribulosemonophosphate(RMP)

CORRECTANSWER:B

SOLUTION:

C 14

C3

C3

https://doubtnut.app.link/nItP02YIW2https://doubtnut.app.link/zvugY5YIW2

In -plants, combineswithribuolose(acceptor

molecule)inthepresenceofRuBisCO(RuBP

carboxylase)andformtwomoleculesof3-

phosphoglycericacidorPGA(firststableproduct).


Q-56-46832044

Photosynthetically active radiation (PAR) represents the following

range of wavelength

(A)340-450nm

(B)400-700nm

(C)500-600nm

(D)400-950nm

CORRECTANSWER:B

C3 CO2

https://doubtnut.app.link/zvugY5YIW2https://doubtnut.app.link/bK2Qz7YIW2

SOLUTION:

Photosyntheticallyactiveregion(PAR)ofsolarradiation

isvisibleregion.Itconsistsofradiationshaving

wavelengthbetween400to700nm.Greenplantsuse

thiswavelengthintheprocessofmanufactureoffood,

i.e.,photosynthesis.


Q-57-46832040

The principle of limiting factors was proposed by:-

(A)Blackmann

(B)Hill

(C)Arnon

(D)Liebig

https://doubtnut.app.link/bK2Qz7YIW2https://doubtnut.app.link/TLcnz9YIW2

CORRECTANSWER:A

SOLUTION:

Theprincipleoflimitingoffactorswasgivenby

blackmann,abritishplantphysiologistin1905,

accordingtohim,lightintesity,carbondioxide

concentrationandtemperaturearethelimitingfactorsin

photosynthesis.Whenaprocessisconditionedastoits

rapiditybyanumberofsepratefactors,therateofthe

processislimitedbythepaceoftheslowestfactor.


Q-58-46832026

Which element is located at the centre of the porpyrin ring in

chlorophyll?

(A)Manganeseandchlorine

https://doubtnut.app.link/TLcnz9YIW2https://doubtnut.app.link/fShzqbZIW2

(B)Calcium

(C)Magnesiumandmolybdenum

(D)Potassium

CORRECTANSWER:C

SOLUTION:

Magnesiumisatthecentreoftheporphyrinringin

chlorophyll.Thegeneralstructureofchlorophyllwas

elucidatedbyhandfischerin1940.


Q-59-46832014

The first acceptor of electrons from an excited chlorophyll molecule

of phtosystem II is

(A)cytochrome

https://doubtnut.app.link/fShzqbZIW2https://doubtnut.app.link/g267oeZIW2

(B)iron-sulphurprotein

(C)ferredoxin

(D)quinone

CORRECTANSWER:D

SOLUTION:

Plastoquinoneisthefirstacceptorofelectronsfroman

excitedchlorophyllmoleculeofphotosystem-II.


https://doubtnut.app.link/g267oeZIW2

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CO C · 2020. 1. 7. · PHOTOSYNTHESIS IN HIGHER PLANTS Revise Most Important Questions to Crack NEET 2020 Download Doubtnut Now Q-1 - 46831993 Phosphoenol pyruvate (PEP) is the primary