CBSE Class 11 Biology Photosynthesis in Higher Plants MCQs Set 05

Question: The chemiosmotic mechanism mediates
a) ATP synthesis
b) Splitting of water
c) Reduction of NADP+
d) Flow of electrons from PS – II to PS – I
Answer: a

Question: Which of the following statement is incorrect regarding pigments?
a) Pigments are substances that have an ability to absorb light at specific wavelengths.
b) Chlorophyll b is the chief pigment associated with photosynthesis.
c) Leaf pigments can be separated by chromatography.
d) Accessory pigments protect chlorophyll a from photo-oxidation.
Answer: b

Question: In PS-I, the reaction centre Chl a has absorption maxima at _____________, while in PS-II the reaction centre Chl a has absorption maxima at ___________.
a) P680, P700
b) P700, P680
c) P800, P600
d) P700, P900
Answer: b

Question: Which one represents the correct empirical equation of photosynthesis?
a) C6H₁₂O₆ + 6O₂ → 6CO₂ + 6H₂O + energy
b) C6H₁₂O₆ + 6O₂ + 6H₂O → 6CO₂ + 12H₂O + energy (Light)
c) 6CO₂ + 6H₂O → 6O₂ + C₆H₁₂O₆ (Chlorophyll, Light)
d) 6CO₂ + 12H₂O → 6O₂ + C6H₁₂O₆ + 6H₂O (Chlorophyll)
Answer: d

Question: The experiment material used by Van Neil to prove that O2 comes out from water was studied on
a) Chlorella pyrenoidosa
b) Cladophora
c) Purple & green sulphur bacteria
d) Blue green algae
Answer: c

Question: Half leaf experiment proves that
a) Light is essential for photosynthesis
b) CO₂ is essential for photosynthesis
c) O₂ releases during photosynthesis
d) Chlorophyll is essential for photosynthesis
Answer: b

Question: Correct equation that represents the 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: In Calvin cycle, RuBisCO incorporates CO₂ into ribulose, 1,5-bisphosphate which rapidly splits into
a) 2 molecules of 3-PGA
b) 2 molecules of 2-PGA
c) 3 molecules of 3-PGA
d) 3 molecules of 2-PGA
Answer: a

Question: Which of the following statement is incorrect?
a) H₂S, not H₂O, is involved in photosynthesis of purple sulphur bacteria.
b) Light and dark reactions are stopped in the absence of light.
c) Calvin cycle occurs in the grana of chloroplast.
d) ATP is produced during light reaction via chemiosmosis.
Answer: c

Question: What is/are the function(s) of accessory pigments?
a) They enable a wider range of wavelength of incoming light to be utilized for photosynthesis.
b) They absorb light and transfer the energy to reaction centre.
c) They protect reaction centre from photo-oxidation.
d) All of the above
Answer: d

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

Question: An energy diagram for the transfer of electrons in the light reactions of photosynthesis in plants is
a) Cyclic photophosphorylation
b) Z-band
c) Z-scheme
d) Non-cyclic photophosphorylation
Answer: c

Question: Which one of the following is incorrect about the activities associated with PS – I and PS – II in non-cyclic photophosphorylation?
a) Water is oxidised in PS – II, but not in PS – I.
b) Photons (light) are needed to activate both PS – I and PS – II.
c) Photolysis of water, formation of ATP + NADPH + H occur.
d) Production of NADPH + H+ is associated with PS – II, but not with PS – I.
Answer: d

Question: One of the earliest experiments on photosynthesis was done in 1770 by Joseph Priestley. He demonstrated that
a) Sun is the ultimate source of energy
b) Water is essential for life
c) Plants & animals “restore” the air for each other
d) Chlorophyll captures light energy
Answer: c

Question: By looking at which internal structure of a plant can you tell whether a plant is C3 or C4?
a) Kranz anatomy
b) Distribution of mesophyll cells
c) Bundle sheath cells only
d) Both (a) and (b)
Answer: d

Question: In photosynthesis, protons accumulate in the
a) Inner membrane space of mitochondria
b) Matrix of mitochondria
c) Lumen of thylakoid
d) Stroma of thylakoid
Answer: c

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

Question: Bundle sheath cells
a) Are rich in RuBisCO
b) Are rich in PEP carboxylase
c) Lack RuBisCO
d) Lack both RuBisCO and PEP carboxylase
Answer: a

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

Question: No. of carbons in the primary CO₂ fixation product of C₄ plant is
a) 2
b) 3
c) 4
d) 5
Answer: c

Question: The primary CO₂ acceptor in C₄ plant is
a) RuBP
b) phosphoenol pyruvate
c) PEP carboxylase
d) PGA
Answer: b

Question: Which of the following statement best support the fact that photorespiration commonly occurs in C₃ plants?
a) C₃ plants don’t possess Kranz anatomy.
b) C₃ plants have usually high CO₂ compensation species.
c) C₃ plants are less efficient in photosynthesis.
d) C₃ plants are characterized by RuBP oxygenase activity under high oxygen supply.
Answer: d

Question: In the leaves of C₄ plants, malic acid formation during CO₂ fixation occurs in the cells of
a) bundle sheath
b) phloem
c) epidermis
d) mesophyll
Answer: d

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

Question: Site of photosynthesis in C₄ plant is
a) mesophyll cells
b) bundle sheath cells
c) Both (a) and (b)
d) Cytosol
Answer: c

Question: Splitting of water is related with
a) photosystem I
b) photosystem II
c) both (a) and (b)
d) cyclic photo-phosphorylation
Answer: b

Question: Fixation of CO₂ molecule through Hatch and Slack pathway requires an enzyme called ________ .
a) PEPcase
b) RuBisCO
c) RuBP carboxylase
d) oxygenase
Answer: a

Question: Photosynthesis is important because
a) it is the primary source of food on earth.
b) it is responsible for release of O2 into the atmosphere by green plants.
c) it is responsible for release of water vapour into the atmosphere.
d) both (a) and (b)
Answer: d

Question: Chloroplast movement is influenced by
a) light exposure
b) dark condition
c) atmospheric condition
d) number of mesophyll cells
Answer: a

Question: Which of the following statement is incorrect?
a) Site of photosynthesis is mesophyll cells of chloroplast.
b) In Z-scheme, movement of electrons is uphill in terms of redox potential scale.
c) In Z-scheme of photosynthesis, the electrons flow from H2O to NADP+.
d) ATP synthesis is linked to development of a proton gradient across a membrane.
Answer: b

Question: Which among the following sentence is incorrect about light reaction?
a) It is also known as ‘photochemical’ phase.
b) It includes light absorption, water splitting, oxygen release, and formation of high-energy intermediates.
c) Reaction centre consist of single molecule of chl a but 2 molecules of chl b.
d) The pigments are organised into two discrete light harvesting complexes within PS–I and PS–II.
Answer: c

Question: Photorespiration is a wasteful process because
a) there is no synthesis of sugars.
b) there is no synthesis of ATP or NADPH.
c) there is no synthesis of phosphoglycerate.
d) both (a) and (b)
Answer: d

Question: Contribution of Ingen-Housz in elucidation of process of photosynthesis is that
a) only green parts of plants exposed to light can convert foul air (CO₂) into pure air (O₂).
b) green plants convert light energy into chemical energy.
c) plants have the capacity to purify foul air.
d) sunlight is the ultimate source of energy for plants and animals.
Answer: a

Question: The total requirement of ATP & NADPH for each molecule of CO₂ fixed & reduced in photosynthesis in the Calvin cycle is
a) 2 ATP & 2 NADPH
b) 2 ATP & 3 NADPH
c) 3 ATP & 2 NADPH
d) 4 ATP & 3 NADPH
Answer: c

Question: In C4 plants, the process by which C₄ acid is converted into C₃ acid in the bundle sheath cell is known as
a) carboxylation
b) regeneration
c) reduction
d) decarboxylation
Answer: d

Question: Plant factors affecting photosynthesis include
a) number, age, size, and orientation of leaves, mesophyll cells and chloroplast, internal CO₂ conc., the amount of chlorophyll.
b) nature of leaves, size of mesophyll cells and light.
c) mesophyll cells, distribution and temperature.
d) quantity of chlorophyll, size of leaves and CO₂.
Answer: a

Question: Which of the following statement is incorrect?
a) Photosystem-I receives electrons from photosystem-II.
b) Photosystem-II receives electrons from photolytic dissociation of water.
c) Formation of NADPH is associated with photosystem-II.
d) Reaction centre of photosystem I is P700.
Answer: a

Question: Photorespiration
a) occurs because oxygen rather than carbon dioxide links to the rubisco enzyme in the Calvin cycle.
b) occurs more in C₄ than in C₃ plants under identical conditions.
c) describes the uptake of CO₂ & the release of oxygen in chloroplasts.
d) All of the above
Answer: a

Question: Which is the primary CO₂ fixation product in C₄ plant?
a) 3-phosphoglyceric acid
b) Oxaloacetic acid
c) Phosphoenol pyruvate
d) RuBP
Answer: b

Question: ATP synthesis, in photosynthesis involves the
a) establishment of a protein gradient.
b) oxidation of water.
c) reduction of NADP+.
d) flow of electrons.
Answer: a

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 of the following statements given below is incorrect ?
a) The C₄ plants respond to higher temperatures while C₃ plants have a much lower temperature optimum.
b) Tropical plants have a higher temperature optimum than the plants adapted to temperate climates.
c) Some C₃ plants are allowed to grow in CO₂ enriched atmosphere that leads to higher yields.
d) Water stress causes the stomata to remain open hence enhancing the CO₂ availability.
Answer: d

Question: The light-driven synthesis of ATP & NADPH, provides energy and reducing power for the
a) conversion of inorganic carbon into organic carbon.
b) fixation of CO₂ into trioses.
c) for the production of sugars.
d) all of the above.
Answer: d

Question: The principle of limiting factors was proposed by
a) Blackman
b) Hill
c) Arnol
d) Liebig
Answer: a

Question: Photosynthesis is a/an
a) physio-chemical process.
b) physical process.
c) chemical process.
d) energy wasting process.
Answer: a

Question: A process that creates an important difference between C₃ & C₄ plants is called____________.
a) Calvin benson cycle
b) photosynthesis
c) photorespiration
d) transpiration
Answer: c

Question: Which one of the following statement correctly describes the cyclic photophosphorylation?
a) Cyclic photophosphorylation has both PS-I and PS-II.
b) Cyclic phosphorylation produces neither ATP nor NADPH + H⁺.
c) Water is the ultimate source of e^– in cyclic phosphorylation.
d) Electrons are cycled in cyclic photophosphorylation.
Answer: d

Question: All of the following statements are incorrect for non-cyclic electron transport system, except
a) Electron transport between PS-II to PS-I produces ATP by substrate level phosphorylation.
b) In PS-II, the oxidation of two water molecules produces four electrons, four proteins, & a single O₂.
c) Water is oxidized & electrons are released by PS-I.
d) PS–II reduces NADP+ to NADPH.
Answer: b

Question: Which was the first CO₂ fixation product formed, in the Calvin experiment, using radioactive labelled 14C in green algal?
a) 2-carbon organic compound
b) 3-carbon organic compound
c) 4-carbon organic compound
d) 5-carbon organic compound
Answer: b