Free NEET Biology multiple-choice questions on Photosynthesis. Attempt each question and reveal the answer with a full explanation.
Photosynthetically Active Radiation (PAR) falls within the wavelength range of: 400 - 700 nm 100 - 400 nm 700 - 1000 nm 200 - 500 nm Oxygenic photosynthesis occurs in : Chlorobium Chromatium Oscillatoria Rhodospirillum What is the primary role of carotenoids in the light-harvesting complex of plants? To protect chlorophyll a from photo-oxidation and expand the absorption spectrum To act as the primary electron donor in the reaction center To fix CO 2 during the dark reaction To catalyze the photolysis of water The 'Compensation Point' in photosynthesis is defined as the point where: Rate of photosynthesis equals the rate of respiration Rate of CO 2 uptake is maximum The plant starts to wilt Rate of water loss equals the rate of water absorption Which pigment acts as the reaction center in Photosystem I (PS I)? P700 P680 Chlorophyll b Carotenoids Chlorophyll a shows maximum absorption of light in which regions of the visible spectrum? Blue and Red Green and Yellow Violet and Orange Yellow and Red Which scientist used a submerged aquatic plant to demonstrate that in bright sunlight, small bubbles were formed around the green parts, while in the dark, they were not? Jan Ingenhousz Joseph Priestley Julius von Sachs Cornelius van Niel To produce one molecule of glucose, the Calvin cycle must turn how many times? 6 3 1 12 In C 3 plants, the primary CO 2 acceptor is a 5-carbon ketose sugar called: Ribulose-1,5-bisphosphate (RuBP) Phosphoenolpyruvate (PEP) 3-phosphoglyceric acid (PGA) Oxaloacetic acid (OAA) In terms of metabolic classification, photosynthesis is an process, while respiration is an process. Anabolic; Catabolic Catabolic; Anabolic Exergonic; Endergonic Reductive; Anabolic Which chlorophyll pigment is considered 'universal' because it is present in all oxygen-evolving photosynthetic organisms? Chlorophyll a Chlorophyll b Chlorophyll c Bacteriochlorophyll In C 4 plants, the primary CO 2 acceptor is a 3-carbon molecule called: Phosphoenol pyruvate (PEP) Ribulose-1,5-bisphosphate (RuBP) Oxaloacetic acid (OAA) 3-phosphoglyceric acid (PGA) Cyclic photophosphorylation results in the formation of : ATP NADPH ATP and NADPH ATP, NADPH and O 2 Identify the correct sequence of steps in the Calvin cycle. Carboxylation, Reduction, Regeneration Reduction, Carboxylation, Regeneration Regeneration, Carboxylation, Reduction Carboxylation, Regeneration, Reduction In Krantz anatomy, the bundle sheath cells are characterized by: Large number of chloroplasts and thick walls Small number of chloroplasts and thin walls No chloroplasts and thick walls Large number of chloroplasts and no intercellular spaces During the formation of one molecule of glucose in C 3 plants, how many ATP and NADPH molecules are consumed? 18 ATP and 12 NADPH 12 ATP and 18 NADPH 30 ATP and 12 NADPH 18 ATP and 18 NADPH What is the average volume of air that a healthy human can expire forcibly after a normal expiration (Expiratory Reserve Volume)? 1000 to 1100 ,mL 500 ,mL 2500 to 3000 ,mL 1100 to 1200 ,mL Vital Capacity (VC) of the lungs can be calculated as: TV + IRV + ERV TV + IRV TV + ERV RV + ERV Which volume of air remains in the lungs even after a forcible expiration and cannot be measured by a simple spirometer? Residual Volume (RV) Expiratory Reserve Volume (ERV) Tidal Volume (TV) Inspiratory Reserve Volume (IRV) The presence of which substance (surfactant) prevents the collapse of alveoli by reducing surface tension? Lecithin Cephalin Albumin Mucin The total volume of air a person can expire after a normal inspiration is called the Expiratory Capacity (EC). It is equal to: TV + ERV TV + IRV VC + RV ERV + RV The 'Functional Residual Capacity' (FRC) of the human lungs includes which of the following volumes? ERV + RV TV + ERV TV + IRV IC + ERV The 'Vital Capacity' of the lungs does NOT include which of the following volumes? Residual Volume ( RV ) Expiratory Reserve Volume ( ERV ) Inspiratory Reserve Volume ( IRV ) Tidal Volume ( TV ) Anoxygenic photosynthesis is characteristic of : Rhodospirillum Spirogyra Chlamydomonas Ulva In a healthy adult human, what is the average value of the Inspiratory Reserve Volume (IRV)? 2500 mL to 3000 mL 1000 mL to 1100 mL 500 mL 1100 mL to 1200 mL The 'Dead Space Volume' in a healthy human adult is approximately: 150 ,mL 500 ,mL 1100 ,mL 50 ,mL Out of the total incident solar radiation, what percentage constitutes Photosynthetically Active Radiation (PAR)? Less than 50 % More than 80 % Exactly 100 % Between 10 % to 20 % Approximately how much carbon is fixed annually in the biosphere through photosynthesis? 4 10 13 kg 4 10 10 kg 4 10 15 kg 4 10 12 kg Succulent plants like cacti often follow which physiological pathway to minimize water loss? CAM (Crassulacean Acid Metabolism) C 3 pathway C 4 pathway Glycolysis Approximately what percentage of the Photosynthetically Active Radiation (PAR) is actually captured by plants for photosynthesis? 2-10 percent 50 percent 1 percent 25 percent The average temperature on Earth decreases progressively from the equator towards the poles and from the plains to the mountains. This variation in temperature affects the distribution of organisms primarily because it influences: Kinetics of enzymes and basal metabolism The rate of decomposition in the soil The availability of light for photosynthesis The osmotic concentration of body fluids Many desert plants have a special photosynthetic pathway called CAM ( Crassulacean Acid Metabolism ). The primary advantage of this pathway is to: Enable their stomata to remain closed during the day Increase the rate of carbon dioxide fixation in high heat Synthesize glucose without the need for light energy Store water in specialized parenchyma cells As compared to a C 3 -plant, how many additional molecules of ATP are needed for net production of one molecule of hexose sugar by C 4 -plants - Zero Six Two Twelve Photosynthesis in C 4 plants is relatively less limited by atmospheric CO 2 levels because The primary fixation of CO 2 is mediated via PEP carboxylase Effective pumping of CO 2 into bundle sheath cells Four carbon acids are the primary initial CO 2 fixation products Rubisco in C 4 plants has higher affinity for CO 2 In a chloroplast the highest number of protons are found in :- Stroma Lumen of thylakoids Inter membrane space Antennae complex In photosystem-I, the first electron acceptor is- Ferredoxin Cytochrome Plastocyanin An iron sulphur protein During photorespiration the oxygen consuming reaction (s) occur in- Stroma of chloroplasts and mitochondria Stroma of chloroplasts and peroxisomes Grana of chloroplasts and peroxisomes Stroma of chloroplasts The first acceptor of electrons from an excited chlorophyll molecule of photosystem II is iron-sulphur protein ferredoxin quinone cytochrome In the leaves of C 4 plants, malic acid formation during CO 2 fixation occurs in the cells of bundle sheath phloem epidermis mesophyll Stroma in the chloroplast of higher plant contains : Chlorophyll Light-independent reaction enzymes Light-dependent reaction enzymes Ribosomes Emerson's enhancement effect and Red drop have been instrumental in the discovery of :- Photophosphorylation and non-cyclic electron transport Two photosystems operating simultaneously Photophosphorylation and cyclic electron transport Oxidative phosphorylation A plant in your garden avoids photorespiratory losses, has improved water use efficiency shows high rates of photosynthesis at high temperatures and has improved efficiency of nitrogen utilisation. In which of the following physiological groups would you assign this plant ? (1) C 3 (2) C 4 (3) CAM (4) Nitrogen fixer Which statement is wrong about photorespiration? RuBP binds with O2 to form two molecules of phosphoglycolate Photorespiration occurs in C3 plants and not C4 plants There is no synthesis of ATP or NADPH RuBisCO has higher affinity for CO2 than O2 In light reaction, plastoquinone facilitates the transfer of electrons from (1) Cytb 6 f complex to PS-I (2) PS-I to NADP + (3) PS-I to ATP synthase (4) PS-II to Cytb 6 f complex The oxygenation activity of RuBisCo enzyme in photorespiration leads to the formation of 1 molecule of 3-C compound 1 molecule of 6-C compound 1 molecule of 4-C compound and 1 molecule of 2-C compound 2 molecules of 3-C compound Which of the following is a proteinaceous and water soluble photosynthetic pigment ? Chlorophyll Xanthophyll Phycocyanin Anthocyanin Which of the following statements is incorrect? Stroma lamellae have PS I only and lack NADP reductase Grana lamellae have both PS I and PS II Cyclic photophosphorylation involves both PS I and PS II Both ATP and NADPH + H + are synthesized during non-cyclic photophosphorylation Which one of the following is not true regarding the release of energy during ATP synthesis through chemiosmosis? It involves: Breakdown of electron gradient Movement of protons across the membrane to the stroma Reduction of NADP to NADPH₂ on the stroma side of the membrane Breakdown of proton gradient How many ATP and NADPH 2 are required for the synthesis of one molecule of Glucose during Calvin cycle? 12 ATP and 12 NADPH 2 18 ATP and 12 NADPH 2 12 ATP and 16 NADPH 2 18 ATP and 16 NADPH 2 Given below are two statements: Statement I: In C 3 plants, some O 2 binds to RuBisCO, hence CO 2 fixation is decreased. Statement II: In C 4 plants, mesophyll cells show very little photorespiration while bundle sheath cells do not show photorespiration. In the light of the above statements, choose the correct answer from the options given below: (1) Both Statement I and Statement II are true (2) Both Statement I and Statement II are false (3) Statement I is true but Statement II is false (4) Statement I is false but Statement II is true Match List I with List II: array llll ; & List-I & ; & List-II A. & Chlorophyll a & (I) & Yellow-green B. & Chlorophyll b & (II) & Yellow C. & Xanthophylls & (III) & Blue-green D. & Carotenoids & (IV) & Yellow to Yellow-orange array Choose the option with all correct matches. A-I, B-IV, C-III, D-II A-III, B-IV, C-II, D-I A-III, B-I, C-II, D-IV A-I, B-II, C-IV, D-III Find the incorrect statement(s) about photosynthesis from the following: A. The water splitting complex is associated with PS I. B. C 4 plants use the C 3 pathway of CO2 fixation as the main biosynthetic pathway. C. In C 4 plants, photorespiration does not occur. D. C 3 plants exhibit ‘Kranz’ anatomy. E. ATP synthesis in chloroplast occurs through chemiosmosis. Choose the answer from the options given below: B and C only B and E only B only A and D only During non-cyclic photophosphorylation (Z-scheme), which of the following is the correct path of electron flow? PS II Plastoquinone Cytochrome b 6f Plastocyanin PS I PS I Plastocyanin Cytochrome b 6f Plastoquinone PS II PS II Plastocyanin Cytochrome b 6f Plastoquinone PS I PS I Plastoquinone Cytochrome b 6f Plastocyanin PS II In C 4 plants, bundle sheath cells are often described as having 'agranal' chloroplasts. What is the primary physiological advantage of this trait? To prevent O 2 evolution near RuBisCO To increase the rate of light absorption To store more starch To facilitate the transport of Malate The temperature coefficient ( Q 10 ) is higher for the 'dark reactions' of photosynthesis compared to the 'light reactions' because: Dark reactions are purely enzymatic Light reactions are purely enzymatic Dark reactions are photochemical Light reactions are temperature independent Using radioactive isotopes, which scientists provided evidence that the oxygen released during photosynthesis comes from water ( H 2O ) and not from carbon dioxide ( CO 2 )? Ruben and Kamen Melvin Calvin Jan Ingenhousz T.W. Engelmann Oxygen is not produced during photosynthesis by Cycas Nostoc Green sulphur bacteria Chara In the Z-scheme of photosynthesis, the movement of electrons from PS II to PS I is 'downhill' in terms of an oxidation-reduction potential scale, except for: The excitation of electrons by light energy in the reaction centers The transfer from Plastoquinone to Cytochrome b 6f The transfer from Plastocyanin to P700 The transfer from Pheophytin to Plastoquinone Photorespiration reaction catalyzed by RuBisCo is shown below: RuBP + O2 -> 3 - Phosphoglycerate + X Identify "X" from the given options: Phosphoenolpyruvate 2-Phosphoglycolate Oxaloacetate Malate Which pigment has absorption peak at 700 nm in the photosynthetic reaction centre PS I (P700)? Chlorophyll b Chlorophyll a Xanthophylls Carotenoids Select the correct sequence of experiments that led to a gradual understanding of photosynthesis in green plants. Absorption spectra of chlorophyll a and b → production of glucose → release of oxygen → role of air Role of air → release of oxygen → production of glucose → absorption spectra of chlorophyll a and b Release of oxygen → production of glucose → absorption spectra of chlorophyll a and b → role of air Production of glucose → role of air → release of oxygen → absorption spectra of chlorophyll a and b How many turns of Calvin cycle are required for the formation of three molecules of glucose? 6 3 1 18 Which of the following statements regarding photorespiration are correct? (a) Do not occur in C3 plants (b) CO2 is consumed and O2 is generated (c) Phosphoglycolate is formed (d) No synthesis of ATP and NADPH Choose the correct answer from the options given below: (a) and (d) only (c) and (d) only (b) and (d) only (a) and (b) only Which of the following is not a product of light reaction of photosynthesis? NADPH NADH ATP Oxygen The first stable product of CO 2 fixation in Sorghum is Oxaloacetic acid Succinic acid Phosphoglyceric acid Pyruvic acid Given below are two statements : Statement I : The primary CO2 acceptor in C4 plants is phosphoenolpyruvate and is found in the mesophyll cells. Statement II : Mesophyll cells of C4 plants lack RuBisCo enzyme. In the light of the above statements, choose the correct answer from the options given below: Both Statement I and Statement II are incorrect Statement I is correct but Statement II is incorrect Statement I is incorrect but Statement II is correct Both Statement I and Statement II are correct What is the role of large bundle sheath cells found around the vascular bundles in C 4 plants? To increase the number of chloroplast for the operation of Calvin cycle To enable the plant to tolerate high temperature To protect the vascular tissue from high light intensity To provide the site for photorespiratory pathway What is the Net Primary Productivity ( NPP ) of an ecosystem? NPP = GPP - R NPP = GPP + R NPP = GPP / R NPP = R - GPP Which micronutrient is required for splitting of water molecule during photosynthesis? Manganese Molybdenum Magnesium Copper The reaction centre in PS II has an absorption maxima at 680 nm 700 nm 660 nm 780 nm Which of the following combinations is required for chemiosmosis? Membrane, proton pump, proton gradient, ATP synthase Membrane, proton pump, proton gradient, NADP synthase Proton pump, electron gradient, ATP synthase Proton pump, electron gradient, NADP synthase Which of the following are required for the dark reaction of photosynthesis? A. Light B. Chlorophyll C. CO2 D. ATP E. NADPH Choose the correct answer from the options given below: A, B and C only B, C and D only C, D and E only D and E only How many molecules of ATP and NADPH are required for every molecule of CO2 fixed in the Calvin cycle? 2 molecules of ATP and 3 molecules of NADPH 2 molecules of ATP and 2 molecules of NADPH 3 molecules of ATP and 3 molecules of NADPH 3 molecules of ATP and 2 molecules of NADPH Which of the following statements about RuBisCO is true? It catalyzes the carboxylation of RuBP It is active only in the dark It has higher affinity for oxygen than carbon dioxide It is an enzyme involved in the photolysis of water The enzyme required for carboxylation in the Calvin cycle is PEP carboxylase RuBP carboxylase - oxygenase Carboxypeptidase Hexokinase How many ATP and NADPH molecules are required to make one molecule of glucose through the Calvin pathway? 12 ATP and 18 NADPH 18 ATP and 12 NADPH 6 ATP and 12 NADPH 24 ATP and 18 NADPH Which of the following processes is responsible for the release of oxygen during photosynthesis? Photolysis of water Reduction of carbon dioxide Photophosphorylation Oxidation of glucose Which of the following is the precursor for the synthesis of Auxins? Tryptophan Methionine Acetyl CoA Mevalonic acid The rate of total production of organic matter during photosynthesis in an ecosystem is known as: Gross Primary Productivity Net Primary Productivity Secondary Productivity Net Community Productivity In the Z-scheme of light reactions, the electrons lost by PS II are immediately replaced by: Electrons from the photolysis of water Electrons from PS I Electrons from NADPH Electrons from atmospheric oxygen The 'Emerson enhancement effect' and Red drop have been instrumental in the discovery of: Two distinct photochemical reactions Photophosphorylation and cyclic electron transport Oxidative phosphorylation Photolysis and water splitting In cyclic photophosphorylation, the electron is circulated within the photosystem and the synthesis of ATP occurs due to the cyclic flow of electrons. This process involves: PS I only PS II only Both PS I and PS II PS I and the stroma lamellae The 'Avena curvature test' is a classic bioassay used for the detection and quantification of which plant hormone? Auxin Gibberellin Cytokinin Abscisic acid The Light Harvesting Complex (LHC) or antennae molecules consist of hundreds of pigment molecules bound to proteins, excluding: One molecule of Chlorophyll a Chlorophyll b Xanthophylls Carotenoids In the C 4 pathway, the 4-carbon acid Malate is transported from the mesophyll cells to the bundle sheath cells. Within the bundle sheath cells, Malate is broken down to release: CO 2 and Pyruvate O 2 and Phosphoenolpyruvate CO 2 and Acetyl CoA Water and O 2 What is the primary reason why photorespiration is considered a wasteful process in C 3 plants? It results in the release of CO 2 with the utilization of ATP and NADPH without sugar synthesis It consumes CO 2 and releases oxygen without generating energy It occurs only at night when light energy is unavailable It leads to the accumulation of toxic ammonia in bundle sheath cells In the chemiosmotic mechanism of ATP synthesis, where does the high concentration of protons ( H + ) accumulate in the chloroplast? Lumen of thylakoids Stroma of chloroplast Intermembrane space of chloroplast Matrix of mitochondria Which of the following statements about the compensation point in photosynthesis is correct? It is the light intensity at which the rate of photosynthesis equals the rate of respiration It is the point where the plant begins to wilt due to water loss It is the maximum rate of photosynthesis achievable by a plant It is the CO 2 concentration where photorespiration stops Which pigment is the 'accessory pigment' that protects chlorophyll a from photo-oxidation? Carotenoids Chlorophyll b Xanthophylls Anthocyanins What is the relationship between Gross Primary Productivity ( GPP ) and Net Primary Productivity ( NPP )? GPP - R = NPP GPP + R = NPP NPP - R = GPP GPP / R = NPP When CO 2 levels are low and O 2 levels are high, the enzyme RuBisCO acts as a/an: Oxygenase Carboxylase Dehydrogenase Phosphatase Which of the following elements is a component of the water-splitting complex in PS II? Manganese and Chlorine Magnesium and Iron Copper and Molybdenum Zinc and Manganese In cyclic photophosphorylation, which of the following is produced? ATP only ATP and NADPH ATP, NADPH , and O 2 NADPH only In C 4 plants, the mesophyll cells are characterized by the presence of PEPcase and the absence of which enzyme? RuBisCO Pyruvate dehydrogenase Malic enzyme NADP Reductase The Oxygen Evolving Complex (OEC) involved in the photolysis of water is located on which side of the thylakoid membrane? Inner side (lumen side) Outer side (stroma side) Embedded within the lipid bilayer center On the surface of the outer envelope membrane Photosystem I (PS I) and Photosystem II (PS II) differ in their reaction centers and electron sources. What is the source of electrons for PS I? Electrons from PS II (via the ETS) Photolysis of water NADPH Atmospheric CO 2 RuBisCO (Ribulose-1,5-bisphosphate carboxylase-oxygenase) is the most abundant protein on Earth. It comprises approximately what percentage of soluble leaf protein? 16% - 50% 5% - 10% 75% - 90% 1% - 2% Which of the following describes the relationship between the absorption spectrum of chlorophyll a and the action spectrum of photosynthesis? They show a close overlap, especially in the blue and red regions. They are completely independent and do not overlap. The action spectrum shows a peak only in the green region where absorption is low. Absorption spectrum peaks are in the yellow and orange regions. The enzyme NADP reductase, which is required for the reduction of NADP + to NADPH + H + , is located on the: Stroma side of the thylakoid membrane Lumen side of the thylakoid membrane Inner mitochondrial membrane Outer chloroplast membrane In C 4 plants, the total number of ATP molecules required to synthesize one molecule of glucose is: 30 18 12 38 Calculate the Net Primary Productivity ( NPP ) if the Gross Primary Productivity ( GPP ) of an ecosystem is 150 kcal/m 2/ yr and the Respiration loss ( R ) is 30 kcal/m 2/ yr . 120 kcal/m 2/ yr 180 kcal/m 2/ yr 5 kcal/m 2/ yr 4500 kcal/m 2/ yr Which of the following is the role of Plastoquinone in the light reaction of photosynthesis? Facilitates the transfer of electrons from PS II to Cytochrome b 6f complex Transfers electrons from PS I to NADP Splits water molecules to release oxygen Fixes CO 2 into a 3-carbon compound In C 4 plants, the decarboxylation of the 4-carbon acid (like Malate) to release CO 2 takes place in the: Bundle sheath cells Mesophyll cells Epidermal cells Guard cells In the process of non-cyclic photophosphorylation, which component acts as a mobile electron carrier between Photosystem II and the Cytochrome b 6f complex? Plastoquinone (PQ) Plastocyanin (PC) Ferredoxin (Fd) Pheophytin Which of the following describes the 'Red Drop' phenomenon observed by Robert Emerson? A sharp decline in quantum yield of photosynthesis in wavelengths longer than 680 nm The increase in photosynthesis when red and far-red light are given together The degradation of chlorophyll pigments under intense red light The closure of stomata under red light illumination The chlorophyll molecule consists of a porphyrin head and a long hydrophobic tail. The tail is composed of a/an: Phytol chain Isoprene unit Glycerol backbone Polypeptide In the C 4 pathway, the enzyme PEP carboxylase (PEPcase) has a much higher affinity for CO 2 than RuBisCO. This allows C 4 plants to: Photosynthesize efficiently even at low CO 2 concentrations Skip the light-dependent reactions entirely Reduce the amount of water lost through transpiration Perform photosynthesis in the dark During the photolysis of water in the thylakoid lumen, which ions besides Manganese ( Mn 2+ ) are essential for the process to occur? Cl - and Ca 2+ Mg 2+ and Fe 2+ Cu 2+ and Zn 2+ K + and Na + In C 4 plants, the bundle sheath cells differ from mesophyll cells in that they: Lack grana in their chloroplasts Contain the enzyme PEP carboxylase Lack the enzyme RuBisCO Are the primary site of O 2 release In chemiosmotic ATP synthesis in chloroplasts, the pH of the thylakoid lumen becomes significantly compared to the stroma. Lower (more acidic) Higher (more basic) Equal Neutral T.W. Engelmann (1843–1909) used a prism to split light into its spectral components and illuminated a green alga, Cladophora , placed in a suspension of aerobic bacteria. In which region did the bacteria primarily accumulate? Blue and red light Green and yellow light Infrared and ultraviolet light Orange and indigo light Chemiosmotic theory of ATP synthesis in the chloroplasts and mitochondria is based on Membrane potential Accumulation of K ions Proton gradient Accumulation of Na ions At what concentration of CO 2 do C 3 plants typically show saturation of their photosynthetic rate? Beyond 450 l/L Beyond 360 l/L Exactly at 100 l/L Below 200 l/L Which of the following ions, along with Manganese ( Mn 2+ ), is essential for the photolysis of water during the light reaction of photosynthesis? Chlorine ( Cl - ) Magnesium ( Mg 2+ ) Potassium ( K + ) Iron ( Fe 2+ ) The bundle sheath cells of C 4 plants like Maize often contain chloroplasts that are 'agranal'. This means they: Lack well-developed grana thylakoids Lack the enzyme RuBisCO Do not perform the Calvin cycle Lack stroma The 'Hill Reaction' refers to the light-driven: Reduction of an electron acceptor by water with the evolution of oxygen Fixation of CO 2 into glucose Synthesis of ATP in the dark Conversion of Pyruvate to Acetyl CoA In C 4 plants, the enzyme RuBisCO is specifically located within the chloroplasts of: Bundle sheath cells Mesophyll cells Epidermal cells Spongy parenchyma Cyclic photophosphorylation occurs only when the light available is of a wavelength: Beyond 680 nm Less than 400 nm Between 400 and 500 nm Exactly 660 nm At what percentage of full sunlight does light saturation typically occur for most terrestrial plants (excluding plants in shade or dense forests)? 10% 25% 50% 100% The reaction center of Photosystem II (PS II) has an absorption peak at: 680 nm 700 nm 660 nm 450 nm The Oxygen Evolving Complex (OEC) responsible for the photolysis of water in Photosystem II requires which of the following sets of ions? Mn 2+ , Cl - , and Ca 2+ Mg 2+ , Fe 2+ , and Cu 2+ Zn 2+ , Mo 2+ , and Cl - Mn 2+ , Mg 2+ , and K + Photorespiration is a process that is initiated when RuBisCO binds with O 2 instead of CO 2 . This typically occurs under conditions of: High O 2 and low CO 2 concentration Low O 2 and high CO 2 concentration Low temperature and high humidity High CO 2 and high nitrogen concentration Photosynthetic Active Radiation (PAR) has the following range of wavelengths 340-450 nm 450-950 nm 500-600 nm 400-700 nm In photorespiration, RuBisCO binds with O 2 to form: One molecule of 3-PGA and one molecule of phosphoglycolate Two molecules of 3-PGA Two molecules of phosphoglycolate One molecule of OAA and one molecule of malate In CAM (Crassulacean Acid Metabolism) plants, the primary acceptor of CO 2 in the dark is: Phosphoenolpyruvate (PEP) Ribulose-1,5-bisphosphate (RuBP) Oxaloacetic acid (OAA) Phosphoglyceric acid (PGA) In the Calvin cycle, the regeneration of one molecule of the CO 2 acceptor, Ribulose-1,5-bisphosphate (RuBP), requires how many molecules of ATP? 1 ATP 2 ATP 3 ATP 1 NADPH The phenomenon where high light intensities lead to a decrease in the rate of photosynthesis and potential damage to the photosynthetic apparatus is called: Solarization Photoperiodism Photorespiration Etiolation The 'accessory pigments' like carotenoids serve a dual purpose. Besides harvesting light, they help the plant by: Preventing photo-oxidation of Chlorophyll a Fixing CO 2 directly Synthesizing ATP Reducing NADP + What are the ideal conditions for C 4 plants to achieve maximum photosynthetic productivity? High temperature and High light intensity Low temperature and Low light intensity High CO 2 and Low temperature Shady environments and High humidity In photorespiration, the first stable product formed is: Phosphoglycolate 3-phosphoglyceric acid (PGA) Oxaloacetic acid Malic acid The Water Splitting Complex (Oxygen Evolving Complex) associated with Photosystem II is physically located on the: Inner side of the thylakoid membrane Outer side of the thylakoid membrane Stroma Inter-membrane space of chloroplast In the pentose phosphate pathway (PPP), what is the primary role of the pathway within a plant cell? Generation of NADPH and pentose sugars Complete oxidation of glucose to CO 2 and H 2O for ATP production Fixation of CO 2 into glucose Conversion of fats into carbohydrates What is the primary reason for the 'Warburg effect' in plants? High concentration of O 2 inhibits photosynthesis Low concentration of CO 2 stimulates photorespiration High light intensity causes chlorophyll solarization Excessive N 2 levels inhibit nitrogen fixation Chlorophyll in chloroplasts is located in - Grana Pyrenoid Stroma Both (1) and (3) During the process of photorespiration, which of the following is the site where the 2-carbon compound Glycolate is converted into Glycine? Peroxisome Chloroplast Mitochondrion Vacuole In the chemiosmotic synthesis of ATP in chloroplasts, for every molecule of ATP produced, how many protons ( H + ) are estimated to pass through the F 0 channel? 3 1 6 12 In the C 2 cycle (photorespiration), the dephosphorylation of phosphoglycolate to glycolate occurs in the: Chloroplast Peroxisome Mitochondria Cytoplasm In the Electron Transport System of Photosystem I, the first membrane-bound electron acceptor is: An Iron-Sulfur (Fe-S) protein Plastoquinone Cytochrome b6 Plastocyanin The herbicide DCMU (3-(3,4-dichlorophenyl)-1,1-dimethylurea) inhibits photosynthesis by blocking electron flow at which site? The Q B binding site of Photosystem II The Oxygen Evolving Complex The reduction of NADP + by Ferredoxin The ATP synthase complex Plastocyanin is a small, mobile, electron-carrying protein used in the photosynthetic electron transport chain. It contains which of the following metal ions? Copper Iron Magnesium Zinc The number of photons of light required to release one molecule of oxygen during photosynthesis is called 'Quantum Requirement'. What is the value of this requirement? 8 4 2 1 The CO 2 compensation point for C 3 plants is generally in the range of: 25 to 100 ppm 0 to 10 ppm 300 to 450 ppm 10 to 50 ppm Who was the scientist who first demonstrated 'photophosphorylation' by showing that isolated chloroplasts could synthesize ATP in the presence of light? Daniel Arnon Melvin Calvin Robert Hill Jan Ingenhousz The enzyme Phosphoenolpyruvate carboxylase (PEPcase) used in C 4 plants has a much lower K m for CO 2 than RuBisCO. This implies that PEPcase has: A higher affinity for CO 2 A lower affinity for CO 2 A higher affinity for O 2 No affinity for CO 2 Manganese is required in : Chlorophyll synthesis Nucleic acid synthesis Plant cell wall formation Photolysis of water during photosynthesis In the photorespiratory pathway ( C 2 cycle), oxygen ( O 2 ) is consumed in which of the following organelles? Chloroplasts and Peroxisomes Chloroplasts and Mitochondria Peroxisomes and Mitochondria Only Chloroplasts Chlorophyll b differs from Chlorophyll a in having which functional group at the third carbon of the second pyrrole ring? -CHO (Aldehyde) -CH 3 (Methyl) -COOH (Carboxyl) -OH (Hydroxyl) In the light reaction of photosynthesis, which molecule acts as the primary electron acceptor from the excited reaction center of Photosystem II (P680)? Pheophytin Plastoquinone Plastocyanin Ferredoxin The molecular formula of Chlorophyll a is: C 55 H 72 O 5N 4Mg C 55 H 70 O 6N 4Mg C 55 H 72 O 6N 4Mg C 54 H 70 O 6N 4Mg The stroma lamellae in chloroplasts are known to lack which of the following components? Both PS II and NADP reductase Only Photosystem II Only NADP reductase PS I and ATP synthase In CAM plants, the initial CO 2 fixation product, Oxaloacetic acid ( OAA ), is reduced to which compound before being stored in the vacuole? Malic acid Pyruvic acid Aspartic acid Citric acid In the Calvin cycle, for every molecule of CO 2 fixed, how many molecules of ATP and NADPH are required respectively? 3 ATP and 2 NADPH 2 ATP and 3 NADPH 3 ATP and 3 NADPH 2 ATP and 2 NADPH In the structure of a Chlorophyll molecule, the Magnesium ( Mg ) atom is located in the center of the: Porphyrin head Phytol tail Pyrrole ring I only Hydrocarbon chain Which of the following processes yields the least amount of energy from a molecule of glucose? Fermentation Aerobic respiration Photorespiration Krebs Cycle The manganese ( Mn ) cluster associated with Photosystem II is involved in which specific reaction? Photolysis of water Reduction of NADP Fixation of CO2 Cyclic photophosphorylation