Objective Questions

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

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

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

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

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

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

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

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)

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

Statement Type Questions

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.

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.

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 the formation of high-energy chemical 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 photochemical light harvesting complexes (LHC) within PS – I and PS – II.

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.

Diagram Type Questions

Question. The given figure of calvin cycle shows the carbon assimilation in C₃ plants. Choose the correct labelling of the carbohydrate molecule (Marked as I, II and III) involved in the Calvin cycle.

I	II	III
(a) RuBP	Triose phosphate	PGA
(b) PGA	RuBP	Triose phosphate
(c) PGA	Triose phosphate	RuBP
(d) RuBP	PGA phosphate	Triose phosphate

Question. The given figure shows the diagramatic representation of the Hatch & Slack pathway few labelling are marked as P, Q and R.

Which of the following option shows the correct labeling of P,Q, and R ?

Question. The diagram given below shows ATP synthesis through chemiosmosis.

Which option shows the correct labelling of A, B, C and D in the diagram ?
(a) A – F₁, B – Thylakoid membrane, C – Photosystem (I), D – Photosystem (II) 
(b) A – F₀, B – Thylakoid membrane, C – Photosystem (I), D – Photosystem (II)
(c) A – F₁, B – Thylakoid membrane,C – Photosystem (II), D – Photosystem (I) 
(d) A – F₀, B – Thylakoid membrane,C – Photosystem (II), D – Photosystem (I)

Question. Study the given graph which shows the action spectrum of A. Superimposed on B spectrum of chlorophyll a. Identify A & B in the graph.

A	B
(a) Rate of respiration	Action spectrum
(b) Rate of respiration	Absorption
(c) Rate of photosynthesis	Action spectrum
(d) Rate of photosynthesis	Absorption

Question. Which one of the following correctly identifies X and Y and and their functions in the given figure of chloroplast ?

Critical Thinking Type Questions

Question. The function of water in photosynthesis is to
(a) absorb light energy.
(b) supply electrons in the light dependent reaction.
(c) transport H⁺ ions in the light independent reactions.
(d) provide O₂ for the light-independent reactions.

Question. Cyclic and non-cyclic flow of e^– is used in plants to
(a) meet the ATP demands of Calvin-cycle.
(b) avoid producing excess NADPH + H⁺.
(c) balance ATP and NADPH + H⁺ ratio in chloroplasts.
(d) All of the above

Question. In a crop field a weedicide is used to remove weeds in order to increase the yield. But the effect of this weedicide is that, it blocks electron transport from photosystem II to photosystem I. This will result in
(a) enhancement of dark reaction.
(b) failure of ATP synthesis.
(c) lack of reduction of NADP⁺.
(d) both (b) and (c)

Question. Reduction of NADP⁺ into NADPH during light reaction occurs in stroma because
(a) NADP reductase enzyme is located on the stroma side of membrane.
(b) PS – I reduces NADP⁺ to NADPH +H⁺ in the stroma.
(c) The pH of the stroma remains constant.
(d) Both (a) and (b) are correct.

Question. Two groups of isolated thylakoids are placed in an acidic bathing solution so that H⁺ diffuses into the thylakoids. They are then transferred to a basic bathing solution, and one group is placed in the light, while the other group is kept in the dark.
Select the choice given below that describes what you expect each group of thylakoids to produce.

	In Light	In Dark
(a)	ATP only	Nothing
(b)	ATP, O2	ATP only
(c)	ATP, O2, glucose	ATP, O2
(d)	ATP, O2	O2

Question. Number of carbons in the primary CO₂ fixation products in C₃ plant is
(a) 3
(b) 4
(c) 5
(d) 6

Question. Which of the following does not participate in the process of photosynthesis?
(a) Red algae
(b) Green algae
(c) Brown algae
(d) None of these

Question. Photosynthesis is the transformation of
(a) light energy to chemical energy.
(b) chemical energy to light energy.
(c) light energy to kinetic energy.
(d) solar energy to potential energy.

Question. Chlorophyll is suited for the capture of light energy because
(a) certain wavelengths of light raise it to an excited state.
(b) in its excited state chlorophyll gives off electrons.
(c) chlorophyll’s structure allows it to attach to thylakoid membranes.
(d) all of the above

Question. Light reaction of photosynthesis results in the formation of
(a) O₂
(b) NADPH + H⁺
(c) ATP
(d) All of these

Question. Breakdown of water during the photosynthesis molecule leads to release of
(a) electron and proton
(b) electron and oxygen
(c) proton and oxygen
(d) electron, proton and oxygen