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150+ Photosynthesis Solved MCQs

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

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1.	The name Melvin Calvin is associated with
A.	synthesis of ATP during photosynthesis
B.	release of water during photosynthesis
C.	carbon fixation during photosynthesis
D.	capture light energy during photosynthesis
Answer» C. carbon fixation during photosynthesis

discuss

2.	Who gave chemical compositions of chlorophyll and carotenoids ?
A.	Park and Biggin
B.	Meyers and French
C.	Willstatter and Stahi
D.	Arnon and Benson
Answer» C. Willstatter and Stahi

discuss

3.	The non-polar part of chlorophyll is
A.	phytol
B.	porphyrin
C.	pyrrol
D.	none above
Answer» A. phytol

discuss

4.	The approximate dimension of chlorophyll porphyrin ring is.
A.	1 Ao square
B.	5 Ao square
C.	10 Ao square
D.	15 Ao square
Answer» D. 15 Ao square

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5.	Photosynthesis is most active in
A.	sunlight
B.	yellow
C.	red
D.	green
Answer» A. sunlight

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6.	Intensity of light increase 20 times, rate of photosynthesis will
A.	increase
B.	not increase
C.	decrease
D.	increase till feed back inhibition.
Answer» D. increase till feed back inhibition.

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7.	Out of the total light energy that is available for plants is
A.	50 %
B.	75 %
C.	25 %
D.	1––2%
Answer» A. 50 %

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8.	One photon is blue light contains....kcal and of red light....kcal
A.	70 ; 40
B.	220 ; 70
C.	10 ; 90
D.	90 ; 10
Answer» D. 90 ; 10

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9.	The most efficient convertor of sunlight is
A.	Potato
B.	Tomato
C.	Sugar cane
D.	Papaya
Answer» C. Sugar cane

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10.	Cyclic photophosphorylation is confined to
A.	Photosystem I
B.	Photosystem II
C.	both a & b
D.	none above
Answer» A. Photosystem I

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11.	For synthesis of one gram of hexose, the land plant consumes.
A.	Only 1/3 of the CO2 of air
B.	Only 1/4 of the CO2 of air
C.	Only 2/3 of the CO2 of air
D.	none of the above
Answer» B. Only 1/4 of the CO2 of air

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12.	For synthesis of one glucose molecule, the number of ATP required are
A.	9 ATP for C3 cycle and 20 ATP for C4 cycle
B.	18 ATP for C3 cycle and 30 ATP for C4 cycle
C.	22 ATP for C3 cycle and 35 ATP for C4 cycle
D.	24 ATP for C3 cycle and 36 ATP for C4 cycle
Answer» B. 18 ATP for C3 cycle and 30 ATP for C4 cycle

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13.	The volume of O2 librated in photosynthesis has the following ratio to CO2.
A.	O2/CO2 = 1
B.	O2/CO2 = 1/2
C.	O2/CO2 = 2/1
D.	O2/CO2 = 3/1
Answer» A. O2/CO2 = 1

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14.	The inhibiting effect of oxygen in C3 plants on photosynthesis is
A.	solarization
B.	photooxidation
C.	Warbug’s effect
D.	none above
Answer» C. Warbug’s effect

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15.	Pick up C4 plant.
A.	Papaya
B.	Potato
C.	Maize
D.	Pea
Answer» C. Maize

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16.	It is advantageous to use a water plant to demonstrate photosynthesis other than a land plant because.
A.	it photosynthesize rapidly
B.	it respires slowly
C.	it does not transpire
D.	O2 bubbles from cut and can be collected over H2O.
Answer» D. O2 bubbles from cut and can be collected over H2O.

discuss

17.	For chlorophyll formation most important are
A.	Fe++ and Ca++
B.	Fe++ and Mg++
C.	Mg++ and Ca++
D.	all the above
Answer» B. Fe++ and Mg++

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18.	Translocation of sugar in angiosperms occur in form of
A.	glucose
B.	starch
C.	lactose
D.	sucrose
Answer» D. sucrose

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19.	Q10 is
A.	respiratory coefficient
B.	photosynthetic coefficient
C.	photosynthetic yield
D.	temperature coeffiecient
Answer» D. temperature coeffiecient

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20.	Photorespiration is favoured by
A.	low temperature
B.	low light intensity
C.	high O2 and low CO2
D.	low O2 and high CO2
Answer» C. high O2 and low CO2

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21.	Quinones are
A.	mobile electron carrier
B.	enzymes of oxidative phosphorylation
C.	enzymes of krebs cycle
D.	none of the above
Answer» A. mobile electron carrier

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22.	During dark reaction, for the fixation of carbon, the three carbon atoms of each molecule of 3 – phosphogylceric acid (PGA) are derived from
A.	RuBP only
B.	CO2 only
C.	RuBP + CO2
D.	RuBP + CO2 + PEP.
Answer» C. RuBP + CO2

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23.	Calvin cycle utilize for fixation of 3 molecules of CO2
A.	9 ATP and 6 NADPH2
B.	8 ATP and 8 NADPH2
C.	9 ATP and 3 NADPH2
D.	6 ATP and 6 NADPH2
Answer» A. 9 ATP and 6 NADPH2

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24.	Chloroplast has maximum quantity of....in stroma
A.	dehydrogenase
B.	RuBP carboxylase
C.	pyruvic carboxylase
D.	hexokinase
Answer» B. RuBP carboxylase

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25.	If thylakoids are removed and kept in culture medium having CO2 and H2O and exposed to light ; they cannot form hexose sugars as end product because.
A.	light trapping device absent
B.	pigments P-700 and P-680 not linked
C.	CO2 assimilating enzymes absent
D.	CO2 assimilation cannot occur in light
Answer» C. CO2 assimilating enzymes absent

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26.	Which of the following plant is efficient converter of solar energy whose net productivity 2-4 kg/m2/yr or even higher.
A.	Wheat
B.	rice
C.	sugarcane
D.	bajra
Answer» C. sugarcane

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27.	The number of photons required to release one mole of O2 in photosynthesis called.
A.	quantum yield
B.	quantum requirement
C.	red drop
D.	Emerson’s effect
Answer» B. quantum requirement

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28.	Calvin cycle represents one of the following phenomenon.
A.	oxidative carboxylation
B.	dark phosphorylation
C.	dark respiration
D.	reductive carboxylation
Answer» D. reductive carboxylation

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29.	Hill reaction takes place
A.	in the absence of CO2
B.	in the presence of carbon dioxide
C.	in the absence of a suitable electron acceptor
D.	none above
Answer» D. none above

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30.	Match the names of scientists given under Column – I with their important contributions given under Column – II ; choose the answer which gives correct combination of the alphabets : Column – I(Scientists) Column – II(Contributions) P. Peter Mitchell (i) Steps of dark reaction of photosynthesis. Q. J.W. Gibbas (ii) Photosynthetic phosphorylation R. Danial Arnon (iii) Concept of free energy S. Melvin Calvin (iv) Chemiosmotic hypothesis (v) Mass flow hypothesis
A.	P = (iv), Q = (iii), R = (ii), S = (i)
B.	P = (iii), Q = (iv), R = (i), S = (i)
C.	P = (iv), Q = (v), R = (iii), S= (ii)
D.	P = (iv), Q = (iii), R = (i), S = (ii)
Answer» A. P = (iv), Q = (iii), R = (ii), S = (i)

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31.	Match Column – I with given under Column – II ; choose the answer which gives correct combination: Column – I(Scientists) Column – II(Contributions) P. A pigment which absorbs red and far-red light (i) Cytochrome Q. Main pigment involved in transfer of electrons in (ii) PEP carboxylase photosynthesis is R. NADPH2 is generated through.... (iii) Photochrome S. Enzyme which fixes CO2 in C4 plants (iv) Photosystems
A.	P = (i), Q = (ii), R = (iii), S = (iv)
B.	P = (iii), Q = (i), R = (iv), S = (iii)
C.	P = (iii), Q = (ii), R = (iii), S= (i)
D.	P = (i), Q = (ii), R = (iv), S = (iii)
Answer» B. P = (iii), Q = (i), R = (iv), S = (iii)

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32.	The basic feature of typical C4 plants showing ‘Kranz’ anatomy is
A.	the presence of chloroplasts in mesophyll and epidermal cells
B.	the presence of chloroplasts in bundle sheath cells
C.	the presence of rudimentary chloroplasts in bundle sheath cells and typical chloroplasts with well-formed grana in mesophyll cells
D.	the presence of typical chloroplasts with well-formed grana in bundle sheath cells and rudimentary chloroplasts in the mesophyll cells
Answer» C. the presence of rudimentary chloroplasts in bundle sheath cells and typical chloroplasts with well-formed grana in mesophyll cells

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33.	A. Six turns of Calvin-cycle result in the production of one molecule of glucose (C6H12O6) R. Three molecules of ribulose 1, 5 – bisphosphate (Ru BP) react with three molecules of carbon dioxide to produce six carbon intermediates.
A.	A is correct and R is its explanation
B.	A is correct but R is not its explanation
C.	A is correct but R is wrong
D.	Both A and R are wrong
Answer» C. A is correct but R is wrong

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34.	Maximum photosynthesis occurs in which of these lights ?
A.	Red
B.	Green
C.	Very high light
D.	Continuous bright light
Answer» A. Red

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35.	In C4 plants showing Kranz anatomy which of the following is correct ?
A.	Bundle sheath cells without grana and mesophyll cells with grana
B.	bundle sheath cells with grana mesophyll cells without grana
C.	both are without grana
D.	both are with grana
Answer» A. Bundle sheath cells without grana and mesophyll cells with grana

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36.	In Blackmann’s ‘Law of Limiting Factors’ the rate of photosynthesis continues to increase with the successive increase in the amounts of
A.	carbon dioxide, light, temperature
B.	temperature, light, carbon dioxide
C.	light, temperature, carbon dioxide
D.	light, carbon dioxide, temperature
Answer» A. carbon dioxide, light, temperature

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37.	Choose the correct statement
A.	Chl a is blue green pigment with formula C55H70O6N4Mg
B.	Chl a is blue green pigment with formula C55H72O5N4Mg
C.	Chl b is yellow green pigment with formula C55H70O5N4Mg
D.	Xanthophyll is pigment with formula C40H60
Answer» B. Chl a is blue green pigment with formula C55H72O5N4Mg

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38.	Chlorophyll a is absent in which of the following photosynthesising organisms ?
A.	Bacteria
B.	Cyanobacteria
C.	Red algae
D.	Brown algae
Answer» A. Bacteria

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39.	Photorespiration in C3 plants starts from.
A.	phosphoglycerate
B.	phosphosglycolate
C.	glycerate
D.	glycine
Answer» B. phosphosglycolate

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40.	Which one of the following is wrong in relation to photorespiration ? It
A.	occurs in chloroplast
B.	occurs in daytime only
C.	is a characteristic of C4 plants
D.	is a characteristic of C3 plants
Answer» C. is a characteristic of C4 plants

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41.	In sugarcane plant CO2 is fixed in malic acid, in which the enzyme that fixes CO2 is
A.	ribulose biphosphate carboxylase
B.	phosphoenol pyruvic acid carboxylase
C.	ribolose phosphate kinase
D.	fructose phosphatase
Answer» B. phosphoenol pyruvic acid carboxylase

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42.	Plants are removed from patients room at night because
A.	they produce CO2 at night in more concentration
B.	they produce CO2 all the time but release O2 also in day time
C.	they consume O2 at night.
D.	they do not photosynthesize at night, therefore fail to deplete CO2 of the room, hence their presence will increase CO2
Answer» B. they produce CO2 all the time but release O2 also in day time

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43.	Who is that scientist who gave the Law of limiting factors ?
A.	Blackman
B.	Hill
C.	Liebig
D.	Von Mohi
Answer» A. Blackman

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44.	Which of the following is correct for chlorophyll of cyanobacteria ?
A.	Chl a = C55H70O6N4 Mg
B.	Chl a = C55H72O5N4 Mg
C.	Chl b = C55H72O6N4 Mg
D.	Xanthophyll = C40H56
Answer» B. Chl a = C55H72O5N4 Mg

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45.	How many electrons are involved for the formation of 1 mole of glucose and 6O2 molecules ?
A.	6
B.	12
C.	18
D.	24
Answer» B. 12

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46.	A. The atmospheric concentration of CO2 at which photosynthesis just compensation point. R. The CO2 compensation point is reached when the amount of CO2 uptake is less than that generated through respiration because the level of CO2 in the atmosphere is more than that required for achieving CO2 compensation point.
A.	If A is correct and R is its explanation
B.	If A is correct but R is not its explanation
C.	If A is correct but R is wrong
D.	If both A and R are correct
Answer» C. If A is correct but R is wrong

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47.	Choose the correct statement.
A.	The C4 plants do not have Rubisco.
B.	Carboxylation of RuBP leads to the formation of PGA and phosphoglycolate.
C.	Decarboxylation of C4 acids occurs in the mesophyll cells.
D.	In CAM plants Calvin’s cycle reactions occur during night.
Answer» C. Decarboxylation of C4 acids occurs in the mesophyll cells.

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48.	Match the names of scientists given under Column – I with their important contributions given under Column – II ; choose the answer which gives correct combination of the alphabets : Column – I(Scientists) Column – II(Contributions) P. Peter Mitchell (i) Law of limiting factor Q. Blackmann (ii) Dark reaction R. Daniel Arnon (iii) Photosynthetic phosphorylation S. Melvin Calvin (iv) Chemiosmotic hypothesis t. Mass flow hyposhesis
A.	P = (iv) Q = (i) R = (iii) S = (ii)
B.	P = (i) Q = (iv) R = (ii) S = (iii)
C.	P = (ii) Q = (i) R = (iii) S = (iv)
D.	P = (iv) Q = (iii) R = (ii) S = (i)
Answer» A. P = (iv) Q = (i) R = (iii) S = (ii)

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49.	Match the following with correct combination P. Carboxylation (i). Oxygen evolution Q. Phosphorylation (ii) Photorespiration R. Photolysis of water (iii) Rubisco S. Phosphoglycolate (iv) Chemosynthesis T. Nitrosomonas (v)ATP
A.	P = (i) Q = (ii) R = (iii) S = (iv) T = (v)
B.	P = (iii) Q = (v) R = (i) S = (ii) T = (iv)
C.	P = (i) Q = (iii) R = (v) S = (iv) T = (i)
D.	P = (i) Q = (iii) R = (iv) S = (ii) T = (v)
Answer» B. P = (iii) Q = (v) R = (i) S = (ii) T = (iv)

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50.	During photosynthessis, plants
A.	absorb O2, release CO2
B.	release O2, absorb CO2
C.	absorb N2, release O2
D.	absorb N2 and release NH3
Answer» B. release O2, absorb CO2

discuss

150+ Photosynthesis Solved MCQs

The name Melvin Calvin is associated with

Who gave chemical compositions of chlorophyll and carotenoids ?

The non-polar part of chlorophyll is

The approximate dimension of chlorophyll porphyrin ring is.

Photosynthesis is most active in

Intensity of light increase 20 times, rate of photosynthesis will

Out of the total light energy that is available for plants is

One photon is blue light contains....kcal and of red light....kcal

The most efficient convertor of sunlight is

Cyclic photophosphorylation is confined to

For synthesis of one gram of hexose, the land plant consumes.

For synthesis of one glucose molecule, the number of ATP required are

The volume of O2 librated in photosynthesis has the following ratio to CO2.

The inhibiting effect of oxygen in C3 plants on photosynthesis is

Pick up C4 plant.

It is advantageous to use a water plant to demonstrate photosynthesis other than a land plant because.

For chlorophyll formation most important are

Translocation of sugar in angiosperms occur in form of

Q10 is

Photorespiration is favoured by

Quinones are

During dark reaction, for the fixation of carbon, the three carbon atoms of each molecule of 3 – phosphogylceric acid (PGA) are derived from

Calvin cycle utilize for fixation of 3 molecules of CO2

Chloroplast has maximum quantity of....in stroma

If thylakoids are removed and kept in culture medium having CO2 and H2O and exposed to light ; they cannot form hexose sugars as end product because.

Which of the following plant is efficient converter of solar energy whose net productivity 2-4 kg/m2/yr or even higher.

The number of photons required to release one mole of O2 in photosynthesis called.

Calvin cycle represents one of the following phenomenon.

Hill reaction takes place

The basic feature of typical C4 plants showing ‘Kranz’ anatomy is

A. Six turns of Calvin-cycle result in the production of one molecule of glucose (C6H12O6) R. Three molecules of ribulose 1, 5 – bisphosphate (Ru BP) react with three molecules of carbon dioxide to produce six carbon intermediates.

Maximum photosynthesis occurs in which of these lights ?

In C4 plants showing Kranz anatomy which of the following is correct ?

In Blackmann’s ‘Law of Limiting Factors’ the rate of photosynthesis continues to increase with the successive increase in the amounts of

Choose the correct statement

Chlorophyll a is absent in which of the following photosynthesising organisms ?

Photorespiration in C3 plants starts from.

Which one of the following is wrong in relation to photorespiration ? It

In sugarcane plant CO2 is fixed in malic acid, in which the enzyme that fixes CO2 is

Plants are removed from patients room at night because

Who is that scientist who gave the Law of limiting factors ?

Which of the following is correct for chlorophyll of cyanobacteria ?

How many electrons are involved for the formation of 1 mole of glucose and 6O2 molecules ?

Choose the correct statement.

Match the following with correct combination P. Carboxylation (i). Oxygen evolution Q. Phosphorylation (ii) Photorespiration R. Photolysis of water (iii) Rubisco S. Phosphoglycolate (iv) Chemosynthesis T. Nitrosomonas (v)ATP

During photosynthessis, plants

Match the following with correct combination
P. Carboxylation (i). Oxygen evolution
Q. Phosphorylation (ii) Photorespiration
R. Photolysis of water (iii) Rubisco
S. Phosphoglycolate (iv) Chemosynthesis
T. Nitrosomonas (v)ATP