CO C · 2020. 1. 7. · PHOTOSYNTHESIS IN HIGHER PLANTS Revise Most Important Questions to Crack...
Transcript of CO C · 2020. 1. 7. · PHOTOSYNTHESIS IN HIGHER PLANTS Revise Most Important Questions to Crack...
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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.
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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.
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Q-5-46832007
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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.
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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.
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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.
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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.
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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.
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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.
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Q-12-46832038
Protochlorophyll differs from chlorophyll in lacking
(A)2hydrogenatomsintwoofitspyrrolerings
(B)2hydrogenatomsintwoofitspyrrolerings
(C)4hydrogenatomsinoneofitspyrrolerings
(D)4hydrogenatomsintwoofitspyrrolerings
CORRECTANSWER:A
SOLUTION:
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Protochlorophylldiffersfromchlorophyllinlacking2
hydrogenatomsinoneofitspyrrolerings.
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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).
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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
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CORRECTANSWER:B
SOLUTION:
Cyclicphotophosphorylationisthattypeoflight
energisedATPsynthesisinwhichelectronexpelledby
excitedphotocentredoesnotreturntothem.Itinvolves
twophotochemicalsystems(PS-IandPS-II)and
producesassimilatorypower(ATPandNADPH).Inboth,
cyclicandnon-cyclicphotophoshorylation,formationof
ATPtakesplace.
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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).
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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).
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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).
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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 −
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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.
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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
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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.
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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
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sugarstakesplace. isprimarilyfixedbyPEP
carboxylasebecausethisenzymehasgreateraffinityto
thanRuBisCO.
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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.
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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.
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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.
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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
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Q-28-30698765
Optimum temperature for photosynthesis is
(A)35 ∘ − 40 ∘C
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(B)
(C)
(D) .
CORRECTANSWER:C
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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
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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
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Q-32-30698758
NADPH2
3P GAL, 3AT P ,3NADPH2
6P GAL, 6AT P ,6NADPH2
18PGAL, 18AT P ,18NADPH2
9P GA, 9ATP ,9NADPH2
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RuBisCo occurs in high quantity as it is
(A)Anoxygenase
(B)Catalysingreversiblereaction
(C)Degradedrapidly
(D)Veryslowactingenzyme.
CORRECTANSWER:D
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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.
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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
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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
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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 +
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photolysisofwateraretransferredtoPS-IIandthenPS-I
viaaseriesofelectroncarriers. ofPS-Ireleases
electronafterabsorbinglightenergyThiselectron
passesthroughchlorophyllX,Fe-S,ferredoxinand
finallyto combineswith
(releasedduringphotolysis)withthehelpofNADP
reductasetoformNADPH.
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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
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(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).
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Q-38-46832045
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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
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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.
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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
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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
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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.
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Q-42-46832002
Anoxygenic photosynthesis is characteristic of
(A)Rhodospirillum
(B)Spirogyra
(C)Chlamydomonas
(D)Ulva
CORRECTANSWER:A
SOLUTION:
Anoxygenicphotosynthesis(inwhich isnotreleased)O2
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isseeninRrhodospirilllumwhichisapurplenon-sulphur
bacteria.Ithelpsanorganismtotraplightenergyand
storeitaschemicalenergy.Otherthanthisanoxygenic
photosynthesiscommonlyoccursinpurplenon-sulphur
bacteriagreensulphur/non-sulphurbacteria,and
heliobacteria,etc.
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Q-43-46832006
Of the total incident solar radiation the proportion of PAR is:
(A)about60%
(B)lessthan50%
(C)morethan80%
(D)about70%
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CORRECTANSWER:B
SOLUTION:
PAR(photosyntheticallyactiveradiation)designatesthe
spectralrangeofsolarradiationfrom400-700nmthat
photosyntheticorganismsareabletouseintheprocess
ofphotosynthesis.Ofthetotalincidentsolarradiationthe
proportionofPARislessthan50%.
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Q-44-46832015
In photosystem-I the first electron acceptor is
(A)cytochrome
(B)plastocyanin
(C)aniron-sulphurprotein
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-
(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
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(Fd)presentatoutersurfaceofthylakoidmembrane.
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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
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(PEP)andthereactionbeingcatalysedbyPEP
carboxylase.
.
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Q-46-46832028
In photosynthesis , energy from light reaction to dark reaction is
transferred in the form of
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(A)ADP
(B)ATP
(C)RuDP
(D)chlorophyll
CORRECTANSWER:B
SOLUTION:
Asaresultoflightreaction,oxygen,NADPHatATPare
formed.Oxygenisreleasedintotheatmospherewhile
NADPHandATPareutilisedforreductionof to
carbohydrateindarkreaction.
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Q-47-46832039
NADPH is generated through
CO2
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(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
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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-
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-
ionicMgatomliesinthecentreofporphyrin,attachedto
nitrogenatomsofpyrrolerings.Chlorophyll-ahasmethyl
groupascarbon3ofpyrroleringandchlorophyll-bhas
foormyl(aldehyde)groupattachedtothisatom.
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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
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SOLUTION:
Ruben,HassidandKamen(1941)usingheavyisotope
ofoxygen, inwater,foundthatoxygenevolvedin
photosynthesiscomesfromwaterevolutionofoxygen
doesnotrequirecarbondioxide.
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Q-50-46832060
Chlorophyll a occurs in
(A)allphotosyntheticautotrophs
(B)inallhigherplants
(C)alloxygenliberatingautotrophs
(D)allplantsexceptfungi
CORRECTANSWER:B
O18
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SOLUTION:
Chlorophyll-a isabluishgreen
pigment,itistheprimaryphotosyntheticpigmentor
universalphotosyntheticpigmentthatoccursinallplants
exceptphotoautotrophicbacteria,i.e.,foundinoxygenic
photoautotrops.
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Q-51-46832011
Cyclic-photophosphorylation results in the formation of
(A)NADPH
(B)ATPandNADPH
(C)ATP,NADPHand
(D)ATP
(C55 − H72O5N4Mg)
O2
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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+
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P700
H +
H +
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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
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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
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carotenoids.
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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
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awardednobelprizein1961inrecomgnitiontohiswork
with isotope.Hediscoveredthecycleinvolvedin
carbonassimilation,knownascalvincycleor -cycle.
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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
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In -plants, combineswithribuolose(acceptor
molecule)inthepresenceofRuBisCO(RuBP
carboxylase)andformtwomoleculesof3-
phosphoglycericacidorPGA(firststableproduct).
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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
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SOLUTION:
Photosyntheticallyactiveregion(PAR)ofsolarradiation
isvisibleregion.Itconsistsofradiationshaving
wavelengthbetween400to700nm.Greenplantsuse
thiswavelengthintheprocessofmanufactureoffood,
i.e.,photosynthesis.
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Q-57-46832040
The principle of limiting factors was proposed by:-
(A)Blackmann
(B)Hill
(C)Arnon
(D)Liebig
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CORRECTANSWER:A
SOLUTION:
Theprincipleoflimitingoffactorswasgivenby
blackmann,abritishplantphysiologistin1905,
accordingtohim,lightintesity,carbondioxide
concentrationandtemperaturearethelimitingfactorsin
photosynthesis.Whenaprocessisconditionedastoits
rapiditybyanumberofsepratefactors,therateofthe
processislimitedbythepaceoftheslowestfactor.
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Q-58-46832026
Which element is located at the centre of the porpyrin ring in
chlorophyll?
(A)Manganeseandchlorine
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(B)Calcium
(C)Magnesiumandmolybdenum
(D)Potassium
CORRECTANSWER:C
SOLUTION:
Magnesiumisatthecentreoftheporphyrinringin
chlorophyll.Thegeneralstructureofchlorophyllwas
elucidatedbyhandfischerin1940.
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Q-59-46832014
The first acceptor of electrons from an excited chlorophyll molecule
of phtosystem II is
(A)cytochrome
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(B)iron-sulphurprotein
(C)ferredoxin
(D)quinone
CORRECTANSWER:D
SOLUTION:
Plastoquinoneisthefirstacceptorofelectronsfroman
excitedchlorophyllmoleculeofphotosystem-II.
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