Chapter:

150+ Photosynthesis Solved MCQs

in Biology

These multiple-choice questions (MCQs) are designed to enhance your knowledge and understanding in the following areas: All India Pre Medical Test (AIPMT) .

Chapters

Take a Test

51.	A plant with low CO2 compensation point is
A.	Atriplex patula
B.	Leucopoa kingii
C.	Gossypium hisrsutum
D.	Tidestromia oblingifolia
Answer» A. Atriplex patula

discuss

52.	Rubisco is an enzyme for
A.	CO2 fixation in dark reaction
B.	photorespiration
C.	regeneration of RuBP
D.	photolysis of water
Answer» B. photorespiration

discuss

53.	Photosynthesis in C4 plants is relatively less limited by atmospheric CO2 levels because :
A.	Four carbon acids are the primary initial CO2 fixation production.
B.	The primary fixation of CO2 is mediated via PEP carboxalase.
C.	Effective pumping of CO2 into bundlesheath cells.
D.	Rubisco in C4 plants has higher affinity for CO2.
Answer» B. The primary fixation of CO2 is mediated via PEP carboxalase.

discuss

54.	Stomata of CAM plants
A.	are always open
B.	open during the day and close at right.
C.	open during the night and close during the day.
D.	never open
Answer» C. open during the night and close during the day.

discuss

55.	The Calvin cycle proceeds in three stages 1. reduction, during which carbohydrate is formed at the expense of the photochemically made ATP and NADPH 2. regeneration, during which the carbon dioxide acceptor ribulose – 1, 5 – biphosphate is formed 3. carboxylation, during which carbon dioxide combines with ribulose – 1, 5 - biophosphate
A.	3-1-2
B.	3-2-1
C.	1-2-3
D.	2-1-3
Answer» A. 3-1-2

discuss

56.	A. Under conditions of high light intensity and limited CO2 supply, photorespiration has a useful role in protecting the plants from photo-oxidative damage. R. If enough CO2 is not available to utilize light energy for carboxylation to proceed, the excess energy may not cause damage to plants.
A.	If Assertion (A) and reason (R) both are correct and R is explanation to A.
B.	If (A) and (R) both are correct but (R) is not an explanation to A.
C.	If A is true but R is false.
D.	If both A and R are false.
Answer» D. If both A and R are false.

discuss

57.	A. Photosynthestically C4 plants are less efficient then C3 plants. R. The operaion of C4 pathway requires the involvement of only bundle-sheath cells.
A.	If Assertion (A) and reason (R) both are correct and R is explanation to A.
B.	If (A) and (R) both are correct but (R) is not an explanation to A.
C.	If A is true but R is false.
D.	If both A and R are false.
Answer» D. If both A and R are false.

discuss

58.	One of the following is electron donor to P680 during light reactions of photosynthesis.
A.	NADPH
B.	Phytochrome
C.	Chiorophyll
D.	Water
Answer» D. Water

discuss

59.	The requirement of assimilatory power to fix 6 molecules of CO2 is
A.	6 ATP, 6 NADPH
B.	12 ATP, 18 NADPH
C.	18 ATP, 18 NADPH
D.	18 ATP, 12 NADPH
Answer» D. 18 ATP, 12 NADPH

discuss

60.	Photorespiration and photosynthesis both require
A.	Organic fuel
B.	chlorophyll
C.	cytochromes
D.	energy
Answer» C. cytochromes

discuss

61.	The chemical structure of chlorophyll ‘a’ varies from chlorophyll ‘b’ due to difference between.
A.	CH3 and C2H5
B.	CH3 and CH2 = CH2
C.	CH3 and CHO
D.	CHO and CH2 = CH2
Answer» C. CH3 and CHO

discuss

62.	Choose the correct combinations of labelling the carbohydrate molecule involved in the Calvin cycle.
A.	A – RuBP, B – Triose phosphate C– PGA
B.	A – PGA, B – RuBP, C Triose phosphate
C.	A – RuBP, B – Triose phosphate, C – PGAL
D.	A – RuBP, B – PGAL, C – Triose phosphate
Answer» D. A – RuBP, B – PGAL, C – Triose phosphate

discuss

63.	Chlorophyll molecules absorb light energy of wavelength
A.	300-400 nm
B.	400-500 nm
C.	600-800 nm
D.	400-500 nm and 600-700 nm
Answer» A. 300-400 nm

discuss

64.	The reduction of ADP to ATP occurs by
A.	oxidation of water
B.	high conc. of H+ ions across the membrane
C.	oxidation of NADPH
D.	release of electron from PS-II to PS-I
Answer» B. high conc. of H+ ions across the membrane

discuss

65.	The process of ATP formation from ADP in the presence of light in chloroplast is called
A.	phosphorylation
B.	autophosphorylation
C.	photophosphorylation
D.	chemophosphorylation
Answer» C. photophosphorylation

discuss

66.	Photolysis of each water molecule in light reaction will yield
A.	2 electrons and 4 proton
B.	4 electrons and 4 protons
C.	4 electrons and 2 protons
D.	2 electrons and 2 protons
Answer» D. 2 electrons and 2 protons

discuss

67.	The enzyme pair common to C3 plants and EMP is
A.	cytochrome oxidase and enolase
B.	aldolase and triose phosphate isomerase
C.	aldolase and enolase
D.	phosphoglyceromutase and triose phosphate isomerase
Answer» B. aldolase and triose phosphate isomerase

discuss

68.	Non-cycle photosphorylation is the main photochemical reaction in green plants because
A.	it produces assimilatory power and oxygen
B.	it initiates photolysis of water of productions of oxygen
C.	it utilizes more energy for oxygen production.
D.	there is no other cycle available.
Answer» A. it produces assimilatory power and oxygen

discuss

69.	................... is the by product of photosynthesis.
A.	O2
B.	H2O
C.	CO2
D.	C6H12O6
Answer» A. O2

discuss

70.	Site of reduction of carbon is
A.	lamellae
B.	thylakoid
C.	grana
D.	stroma
Answer» D. stroma

discuss

71.	In C4 plants, the primary CO2 acceptor is
A.	3 - PGA
B.	Oxalo acetic acid
C.	RuBP
D.	PEP
Answer» D. PEP

discuss

72.	It is estimated that about 85% of the earth’s photosynthetic activity is carried out by
A.	tree
B.	savannas
C.	phytoplanktons
D.	herbaceous plants
Answer» C. phytoplanktons

discuss

73.	In an experiment demonstrating the evolution of oxygen in Hydrilla, Sodium bicarbonate is added to water in the experimental set-up. What would happen if all other conditions are favourable ?
A.	Amount of oxygen evolved decreases as carbon dioxide in water is absorbed by sodium bicarbonate.
B.	Amount of oxygen evolved increases as the avilability of carbon dioxide increases
C.	Amount of oxygen evolved decreases as the avilability of carbon dioxide increases
D.	Amount of oxygen evolved increases as carbon dioxide in water is absorbed by sodium bicarbonate
Answer» D. Amount of oxygen evolved increases as carbon dioxide in water is absorbed by sodium bicarbonate

discuss

74.	In C4 plants, the bundle sheath cells.
A.	have thin walls to facilitate gaseous exchange
B.	have large intercellular spaces
C.	are rich in PEP carboxylase
D.	have a high density of chloroplasts
Answer» D. have a high density of chloroplasts

discuss

75.	In chlorophyll structure four pyrole rings are united with Mg by their atoms of
A.	N
B.	C
C.	H
D.	O
Answer» A. N

discuss

76.	The fixation and reduction of CO2 occur in preence of
A.	ATP
B.	ATP and NADPH
C.	NADPH, chlorophyll and water
D.	ATP, NADPH and light
Answer» B. ATP and NADPH

discuss

77.	Sugar moves in phloem vessels as ______.
A.	cellulose
B.	glucose
C.	starch
D.	sucrose
Answer» D. sucrose

discuss

78.	____ ions help in photolysis of water.
A.	Mn++
B.	Mg++
C.	Cl-
D.	both (a) and (c)
Answer» D. both (a) and (c)

discuss

79.	RUBISCO enzyme is also called as ______.
A.	carboxy tetra mutase
B.	carboxy di mutase
C.	carboxy tri mutase
D.	carboxy uni mutase
Answer» B. carboxy di mutase

discuss

80.	______ is precursor for abscissic acid (ABA)
A.	Zeatin
B.	Lutein
C.	Violaxanthin
D.	Mevalonic acid
Answer» C. Violaxanthin

discuss

81.	In young leaves ratio of carotene to Xanthophyll is ____.
A.	2 : 1
B.	3: 1
C.	1: 3
D.	1: 2
Answer» D. 1: 2

discuss

82.	Which of the following pigments contains open pyrolle ring?
A.	Phycobilin
B.	Xanthophylls
C.	Chlorophylls
D.	-carotene
Answer» A. Phycobilin

discuss

83.	In which of the following light, rate of photosynthesis is maximum?
A.	white
B.	discontinuous white
C.	red
D.	blue
Answer» B. discontinuous white

discuss

84.	Quantum yield of photosynthesis is ______.
A.	13.5 %
B.	8 %
C.	13%
D.	12.5%
Answer» D. 12.5%

discuss

85.	During light phase of photosynthesis ______ is oxidized and ______ is reduced.
A.	CO2 and Water
B.	Water and CO2
C.	Water and NADP
D.	NADPH2 and CO2
Answer» C. Water and NADP

discuss

86.	During dark phase of photosynthesis ______ is oxidized and ______ is reduced
A.	CO2 and Water
B.	Water and CO2
C.	Water and NADP
D.	NADPH2 and CO2
Answer» D. NADPH2 and CO2

discuss

87.	The visible product of photosynthesis is ______.
A.	glucose
B.	cellulose
C.	starch
D.	fructose
Answer» C. starch

discuss

88.	To produce 3 glucose molecules ______ ATP and ______ NADPH2 molecules are required.
A.	54, 36
B.	54, 30
C.	36, 60
D.	18, 12
Answer» A. 54, 36

discuss

89.	Glycolytic reversal is a part of ______.
A.	aerobic respiration
B.	anaerobic respiration
C.	light phase of photosynthesis
D.	dark phase of photosynthesis
Answer» D. dark phase of photosynthesis

discuss

90.	RuBp carboxylase acts as RuBp carboxygenase at ______ CO2 conc. And ______ O2 conc.
A.	low, low
B.	low, hig
C.	high, high
D.	high, low
Answer» B. low, hig

discuss

91.	The source of CO2 during calvin cycle in C4 plant is
A.	Malic acid
B.	OAA
C.	PEP
D.	RuBP
Answer» A. Malic acid

discuss

92.	Dicot which follow C4 pathway is____.
A.	wheat
B.	Amranthus
C.	Maize
D.	Mango
Answer» B. Amranthus

discuss

93.	Absorption spectrum of chlorophyll is maximum in _____ light.
A.	red
B.	blue
C.	yellow
D.	blue-violet
Answer» B. blue

discuss

94.	The oxygen molecule in glucose formed during photosynthesis comes from
A.	Water
B.	Organic acids
C.	CO2
D.	atmosphere
Answer» C. CO2

discuss

95.	Dimorphic chloroplast are present in ______.
A.	zea may
B.	sacchrum officinale
C.	sorghum bicolor
D.	all of these
Answer» D. all of these

discuss

96.	Red pigment in tomato is
A.	 -carotene
B.	Anthocyanin
C.	Lycopene
D.	Lutein
Answer» C. Lycopene

discuss

97.	Solarisation refers to ______.
A.	formation of sugar with help of water and energy
B.	destruction of chlorophyll
C.	synthesis of chl.
D.	both b and c
Answer» B. destruction of chlorophyll

discuss

98.	Dark reaction requires light reaction for
A.	carboxylation of RUBP
B.	regeneration of RuBP
C.	reduction of PGA
D.	formation of hexose sugar
Answer» C. reduction of PGA

discuss

99.	Emerson effect proves
A.	concept of two photosystem in plant
B.	photophosphorylation
C.	photorespiration
D.	there are light and dark reaction in photosynthesis
Answer» A. concept of two photosystem in plant

discuss

100.	Name a plant which do not perform photosynthesis is
A.	Algae
B.	Bryophyllum
C.	cuscutta
D.	Pitcher plant
Answer» D. Pitcher plant

discuss

150+ Photosynthesis Solved MCQs

A plant with low CO2 compensation point is

Rubisco is an enzyme for

Photosynthesis in C4 plants is relatively less limited by atmospheric CO2 levels because :

Stomata of CAM plants

A. Under conditions of high light intensity and limited CO2 supply, photorespiration has a useful role in protecting the plants from photo-oxidative damage. R. If enough CO2 is not available to utilize light energy for carboxylation to proceed, the excess energy may not cause damage to plants.

A. Photosynthestically C4 plants are less efficient then C3 plants. R. The operaion of C4 pathway requires the involvement of only bundle-sheath cells.

One of the following is electron donor to P680 during light reactions of photosynthesis.

The requirement of assimilatory power to fix 6 molecules of CO2 is

Photorespiration and photosynthesis both require

The chemical structure of chlorophyll ‘a’ varies from chlorophyll ‘b’ due to difference between.

Choose the correct combinations of labelling the carbohydrate molecule involved in the Calvin cycle.

Chlorophyll molecules absorb light energy of wavelength

The reduction of ADP to ATP occurs by

The process of ATP formation from ADP in the presence of light in chloroplast is called

Photolysis of each water molecule in light reaction will yield

The enzyme pair common to C3 plants and EMP is

Non-cycle photosphorylation is the main photochemical reaction in green plants because

................... is the by product of photosynthesis.

Site of reduction of carbon is

In C4 plants, the primary CO2 acceptor is

It is estimated that about 85% of the earth’s photosynthetic activity is carried out by

In an experiment demonstrating the evolution of oxygen in Hydrilla, Sodium bicarbonate is added to water in the experimental set-up. What would happen if all other conditions are favourable ?

In C4 plants, the bundle sheath cells.

In chlorophyll structure four pyrole rings are united with Mg by their atoms of

The fixation and reduction of CO2 occur in preence of

Sugar moves in phloem vessels as ______.

____ ions help in photolysis of water.

RUBISCO enzyme is also called as ______.

______ is precursor for abscissic acid (ABA)

In young leaves ratio of carotene to Xanthophyll is ____.

Which of the following pigments contains open pyrolle ring?

In which of the following light, rate of photosynthesis is maximum?

Quantum yield of photosynthesis is ______.

During light phase of photosynthesis ______ is oxidized and ______ is reduced.

During dark phase of photosynthesis ______ is oxidized and ______ is reduced

The visible product of photosynthesis is ______.

To produce 3 glucose molecules ______ ATP and ______ NADPH2 molecules are required.

Glycolytic reversal is a part of ______.

RuBp carboxylase acts as RuBp carboxygenase at ______ CO2 conc. And ______ O2 conc.

The source of CO2 during calvin cycle in C4 plant is

Dicot which follow C4 pathway is____.

Absorption spectrum of chlorophyll is maximum in _____ light.

The oxygen molecule in glucose formed during photosynthesis comes from

Dimorphic chloroplast are present in ______.

Red pigment in tomato is

Solarisation refers to ______.

Dark reaction requires light reaction for

Emerson effect proves

Name a plant which do not perform photosynthesis is

During light phase of photosynthesis is oxidized and is reduced.

During dark phase of photosynthesis is oxidized and is reduced

To produce 3 glucose molecules ATP and NADPH2 molecules are required.

RuBp carboxylase acts as RuBp carboxygenase at CO2 conc. And O2 conc.