Plant Physiology
- Which of the following statements about RuBisCO is true? Answer: 4. It catalyzes the carboxylation of RuBP. Key idea: RuBisCO is the carboxylating enzyme of the Calvin cycle. It catalyses carboxyla... 1
- Read the following statements on plant growth and development.A. Parthenocarpy can be induced by auxins.B. Plant growth regulators can be involved in promotion as well as inhibition of growth.C. Dedifferentiation is a pre-requisite for re-differentia… Answer: 1. A, B, C only Key idea: Check each statement. A true: auxins can induce parthenocarpy. B true: PGRs may promote or inhibit growth.... 1
- Match List I with List II :List I: A. Chlorophyll a; B. Chlorophyll b; C. Xanthophylls; D. CarotenoidsList II: I. Yellow-green; II. Yellow; III. Blue-green; IV. Yellow to Yellow-orangeChoose the option with all correct matches. Answer: 2. A-III, B-I, C-II, D-IV Chlorophyll a: blue-green (III) Chlorophyll b: yellow-green (I) Xanthophylls: yellow (II) Carotenoids: yel... 1
- Which one of the following phytohormones promotes nutrient mobilization which helps in the delay of leaf senescence in plants? Answer: 4. Cytokinin Key idea: Cytokinins delay leaf senescence by promoting nutrient mobilisation. Ethylene and abscisic acid promote senes... 1
- The complex II of mitochondrial electron transport chain is also known as Answer: 2. Succinate dehydrogenase Key idea: Complex II of the electron transport chain is succinate dehydrogenase. It is the Krebs cycle en... 1
- 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 photorespira… Answer: 4. Statement I is true but Statement II is false Key idea: O₂ competes with CO₂ for RuBisCO in C₃ plants, but C₄ plants avoid photor... 1
- Which of the following are fused in somatic hybridization involving two varieties of plants? Answer: 4. Protoplasts Key idea: in somatic hybridization, protoplasts of two varieties or species are fused. Cell walls are removed with en... 1
- Spraying sugarcane crop with which of the following plant growth regulators, increases the length of stem, thus, increasing the yield? Answer: 3. Gibberellin Key idea: gibberellins cause stem elongation. Spraying sugarcane with gibberellin increases internode length, so more... 1
- Match List I with List IIList I: A. Citric acid cycle; B. Glycolysis; C. Electron transport system; D. Proton gradientList II: I. Cytoplasm; II. Mitochondrial matrix; III. Intermembrane space of mitochondria; IV. Inner mitochondrial membraneChoose th… Answer: 3. A-II, B-I, C-IV, D-III Key idea: match each process with its location in the cell. Citric acid cycle: mitochondrial matrix (II).... 1
- Identify the step in tricarboxylic acid cycle, which does not involve oxidation of substrate. Answer: 4. Succinyl-CoA → Succinic acid Key idea: oxidation steps in the TCA cycle produce NADH or FADH₂ . Isocitrate to α -ketoglutarate (N... 1
- Which of the following are required for the dark reaction of photosynthesis?A. LightB. ChlorophyllC. CO_2D. ATPE. NADPHChoose the correct answer from the options given below: Answer: 4. C, D and E only Key idea: the dark (biosynthetic) reaction uses the ATP and NADPH made in the light reaction, together with CO₂ .... 1
- The capacity to generate a whole plant from any cell of the plant is called: Answer: 2. Totipotency Key idea: the ability of a single plant cell to grow into a complete plant is totipotency. Micropropagation is the te... 1
- Formation of interfascicular cambium from fully developed parenchyma cells is an example for Answer: 4. Dedifferentiation Key idea: mature cells that regain the ability to divide undergo dedifferentiation. Interfascicular cambium for... 1
- How many molecules of ATP and NADPH are required for every molecule of CO_2 fixed in the Calvin cycle? Answer: 1. 3 molecules of ATP and 2 molecules of NADPH Key idea: fixing one CO₂ in the Calvin cycle costs 3 ATP and 2 NADPH. One CO₂ joins R... 1
- Auxin is used by gardeners to prepare weed-free lawns. But no damage is caused to grass as auxin Answer: 4. does not affect mature monocotyledonous plants. Key idea: synthetic auxins like 2,4-D kill dicot weeds but not monocot crops or g... 1
- Match List I with List II :List I | List IIA. Cohesion | I. More attraction in liquid phaseB. Adhesion | II. Mutual attraction among water moleculesC. Surface tension | III. Water loss in liquid phaseD. Guttation | IV. Attraction towards polar surfac… Answer: 2. A-II, B-IV, C-I, D-III Key idea: Match each term with its meaning. Cohesion: mutual attraction among water molecules (II). Adhesi... 1
- Match List I with List II :List I | List IIA. Oxidative decarboxylation | I. Citrate synthaseB. Glycolysis | II. Pyruvate dehydrogenaseC. Oxidative phosphorylation | III. Electron transport systemD. Tricarboxylic acid cycle | IV. EMP pathwayChoose th… Answer: 1. A-II, B-IV, C-III, D-I Key idea: Match the process with its enzyme or pathway. Oxidative decarboxylation: pyruvate dehydrogenase... 1
- In tissue culture experiments, leaf mesophyll cells are put in a culture medium to form callus. This phenomenon may be called as : Answer: 3. Dedifferentiation Key idea: When mature, differentiated cells (such as leaf mesophyll) go back to a meristematic state and divide... 1
- The reaction centre in PS II has an absorption maxima at Answer: 2. 680 nm Key idea: The reaction centre of PS II is P680, with absorption maximum at 680 nm. The reaction centre of PS I is P700 (70... 1
- Which of the following combinations is required for chemiosmosis? Answer: 2. membrane, proton pump, proton gradient, ATP synthase Key idea: Chemiosmosis needs a membrane, a proton pump, a proton gradient an... 1
- Match List I with List II :List I | List IIA. Iron | I. Synthesis of auxinB. Zinc | II. Component of nitrate reductaseC. Boron | III. Activator of catalaseD. Molybdenum | IV. Cell elongation and differentiationChoose the correct answer from the optio… Answer: 4. A-III, B-I, C-IV, D-II Key idea: Match each element with its role. Iron: activator of catalase (III). Zinc: needed for synthesis... 1
- Spraying of which of the following phytohormone on juvenile conifers helps in hastening the maturity period, that leads to early seed production? Answer: 3. Gibberellic Acid Key idea: Spraying gibberellic acid (GA) on juvenile conifers hastens maturity, so they produce seeds early. ABA... 1
- Given below are two statements :Statement I : The forces generated by transpiration can lift a xylem-sized column of water over 130 meters height.Statement II : Transpiration cools leaf surfaces sometimes 10 to 15 degrees, by evaporative cooling.In t… Answer: 2. Both Statement I and Statement II are correct. Key idea: Both statements are standard facts about transpiration. Statement I is c... 1
- How many ATP and NADPH_2 are required for the synthesis of one molecule of Glucose during Calvin cycle? Answer: 3. 18 ATP and 12 NADPH ₂ Key idea: One CO₂ fixed in the Calvin cycle needs 3 ATP and 2 NADPH. Glucose has 6 carbons, so 6 turns are... 1