CBSE Class 11 Biology Photosynthesis in Higher Plants MCQs Set 06

Question: The light-driven synthesis of ATP & NADPH provides energy and reducing power for
a) Conversion of inorganic carbon into organic carbon
b) Fixation of CO₂ into trioses
c) Production of sugars
d) All of the above
Answer: d

Question: Correct equation representing photolysis of water is
a) 2H₂O → 4H⁺ + O₂ + 4e⁻
b) H₂O → 4H⁺ + O₂ + 4e⁻
c) 4H₂O → 4H⁺ + O₂ + 4e⁻
d) 2H₂O → 4H⁺ + 2O₂ + 2e⁻
Answer: a

Question: Electrons are picked up by an electron acceptor which passes them to an ETS consisting of
a) Phytochromes
b) Cytochromes
c) Z-scheme
d) Redox potential scale
Answer: b

Question: Photosynthesis is important because
a) It is the primary source of food
b) It releases O₂ into the atmosphere
c) It releases water vapour
d) Both a and b
Answer: d

Question: The light harvesting complex (LHC) is made up of
a) One molecule of Chl a
b) Few molecules of Chl a
c) Hundreds of pigment molecules bound to proteins
d) Chl a + Chl c + protein + DNA
Answer: c

Question: The experiment of Van Niel proving that O₂ comes from water was done on
a) Chlorella pyrenoidosa
b) Cladophora
c) Purple & green sulphur bacteria
d) Blue-green algae
Answer: c

Question: In PS-I the reaction centre Chl a absorbs at ______, while in PS-II it absorbs at ______.
a) P680, P700
b) P700, P680
c) P800, P600
d) P700, P900
Answer: b

Question: How can we separate leaf pigments of a green plant?
a) Column chromatography
b) Paper chromatography
c) Electrophoresis
d) Radio-isotopes
Answer: b

Question: ATP synthesis during photosynthesis involves
a) Establishment of a proton gradient
b) Oxidation of water
c) Reduction of NADP⁺
d) Flow of electrons
Answer: a

Question: Priestley’s experiment demonstrated that
a) Sun is the ultimate energy source
b) Water is essential for life
c) Plants & animals restore air for each other
d) Chlorophyll captures light energy
Answer: c

Statement Type Questions

Question: Which of the following statement(s) is/are correct about RuBisCO?
a) It catalyzes the fixation of CO₂
b) It has oxygenation & carboxylation both activity
c) It is the most abundant protein on earth
d) All of the above
Answer: d

Question: Which one of the following statements is incorrect in relation to photorespiration?
a) It is a characteristic of C₃ plants
b) RuBP binds with O₂ to form phosphoglycerate & phosphoglycolate
c) There is synthesis of ATP or NADPH
d) It occurs in daytime only
Answer: c

Question: Which of the following statements regarding “splitting of water’’ is/are correct?
a) One
b) Two
c) Three
d) All
Answer: d

Question: Why are C₄ plants special?
a) (i) and (ii)
b) (i), (iii) and (iv)
c) (i), (ii), (iii) and (iv)
d) All of these
Answer: d

Assertion/Reason Type Questions

In the following questions, a statement of Assertion is followed by a statement of Reason.
(a) If both Assertion and Reason are true and the Reason is the correct explanation of the Assertion.
(b) If both Assertion and Reason are true but the Reason is not the correct explanation of the Assertion.
(c) If Assertion is true but Reason is false.
(d) If both Assertion and Reason are false.

Question: Assertion: C₄ pathway of CO₂ fixation is found in some tropical plants.
Reason: In this pathway, CO₂ is fixed by 3C compound.
Answer: b

Question: Assertion: Bacterial photosynthesis occurs by utilizing wavelength longer than 700 nm.
Reason: Here reaction centre is B-890.
Answer: b

Question: Assertion : Cyclic pathway of photosynthesis first appeared in some eubacterial species.
Reason : Oxygen started accumulating in the atmosphere after the non-cyclic pathway of photosynthesis evolved.
Answer: b

Matching Type Questions

Question: Which of the following pair is mismatched?
(a) Photosystem I – Uses the P₇₀₀ molecule in its photocenter.
(b) Antenna complex – Contains hundreds of pigment molecule.
(c) PGA – 3- carbon compound.
(d) Dark reaction – Takes place in the grana of the chloroplast.
Answer: d

Question: Match column-I with column-II and choose the correct combination from the options given below.

Column -I                                                                        Column -II
A. Oxygen evolving complex ferric oxalate                      I. Pigments
B. Proton gradient concentration                                     II. High oxygen 
C. Absorb light at specific wavelengths.                          III. ATP synthesis 
D. Photorespiration                                                         IV. Photolysis of water

(a) A – IV; B – III; C – I; D – II
(b) A – IV; B – I; C – III; D – II
(c) A – II; B – I; C – IV; D – III
(d) A – II; B – IV; C – III; D – I
Answer: a

Question: Which of the following is incorrectly matched?
(a) Sorghum — Kranz anatomy
(b) PS – II — P₇₀₀
(c) Photorespiration — C₃ plants
(d) PEP carboxylase — Mesophyll cells
Answer: a

Critical Thinking Type Questions

Question: The reactions of Calvin cycle not directly dependent on light, but they usually do not occur at night. Why?
(a) Night is often too cold for these reactions to occur.
(b) CO₂ concentration in night is too high for these reactions to occur.
(c) Plants usually open their stomata at night.
(d) Calvin cycle is dependent on the products of light reaction.
Answer: d

Question: Chloroplasts are disrupted and the stroma separated from the lamellae. The isolated stroma will fix CO₂ if it is supplied with
(a) O₂
(b) RuBisCO
(c) light
(d) ATP + NADPH
Answer: d

Question: Which of following ratio is correct for the production of one molecule of glucose through 6 rounds of Calvin cycle?

    CO₂   ATP     NAD PH₂
(a) 1           2           2
(b) 6         18         12
(c) 6         12         18
(d) 5          6            9
Answer: b

Question: In an experiment, the CO₂ available to a C₄ plant was labelled with a radioactive isotope and the amount of radioactivity in the chloroplast was measured. As photosynthesis preceeded, in which of the following molecules did the radioactivity first appear?
(a) Oxaloacetic acid
(b) PEP
(c) Malic acid
(d) RuBP
Answer: a

Question: According to Blackman’s law of limiting factor, at any given time, photosynthesis can be limited by
(a) light only
(b) CO₂ concentration only
(c) both light and CO₂ concentration
(d) either by light or by CO₂
Answer: d

Question: Why, at higher light intensities, gradually photosynthesis rate does not show further increase?
(a) Higher light intensity activate more chlorophylls.
(b) Higher light intensity causes more transpiration.
(c) No need of more sugar formation.
(d) Other factors become limiting.
Answer: c

Question: In C₄ (sugarcane plant) plant,14CO₂ is fixed in malic acid in which the enzyme that fixes CO₂ is
(a) fructose phosphatase
(b) ribulose biphosphate carboxylase
(c) phosphoenol pyruvic acid carboxylase
(d) ribulose phosphate kinase
Answer: c

Question: A student sets up an experiment on photosynthesis as follows:
He takes soda water in a glass tumbler and add chlorophyll extracts into the contents and keeps the tumbler exposed to sunlight hoping that he has provided necessary ingredients for photosynthesis to proceed (viz., CO₂, H₂O, chlorophyll and light). What do you think what will happen after, say, a few hours of exposure of light?
(a) Photosynthesis will take place and glucose will be produced.
(b) Photosynthesis will take place and starch will be produced which will turn the mixture turbid.
(c) Photosynthesis will not take place because CO₂ dissolved in soda water escapes into the atmosphere.
(d) Photosynthesis will not take place because intact chloroplasts are needed for the process.
Answer: d

Question: ADP is phosphorylated and NADP is reduced, this happens during.
(a) dark phase of photosynthesis
(b) light phase of photosynthesis
(c) Photorespiration
(d) Calvin cycle
Answer: b

Question: During the light stage of photosynthesis, the photoactivated pigment removes an electron from the hydroxylation derived from the water molecule.
The fate of the free hydroxyl radical is that it
(a) is broken down into oxygen and a free radical of hydrogen.
(b) is used to raise the activation level of chlorophyll by donating a positive charge.
(c) is used to produce adenosine triphosphate from adenosine diphosphate.
(d) reduces carbon dioxide to sugar.
Answer: a