Plant Physiology
- Given below are two statements : One is labelled as Assertion A and the other is labelled as Reason R :Assertion A : ATP is used at two steps in glycolysis.Reason R : First ATP is used in converting glucose into glucose-6-phosphate and second ATP is… Answer: 2. Both A and R are true and R is the correct explanation of A. Key idea: Two ATP molecules are invested in the preparatory phase of... 1
- Which micronutrient is required for splitting of water molecule during photosynthesis? Answer: 2. manganese Key idea: Manganese (Mn) is needed for the water-splitting (photolysis) step of the light reaction, which releases O₂ ,... 1
- Which hormone promotes internode/petiole elongation in deep water rice? Answer: 4. Ethylene Key idea: In deep water rice, submergence raises ethylene levels, and ethylene promotes rapid elongation of internodes a... 1
- What is the role of large bundle shealth cells found around the vascular bundles in C_4 plants ? Answer: 3. To increase the number of chloroplast for the operation of Calvin cycle The large bundle sheath cells of C₄ plants hold many chlo... 1
- Given below are two statements :Statement I :The primary CO_2 acceptor in C_4 plants is phosphoenolpyruvate and is found in the mesophyll cells.Statement II :Mesophyll cells of C_4 plants lack RuBisCo enzyme.In the light of the above statements, choo… Answer: 2. Both Statement I and Statement II are correct Statement I: in C₄ plants PEP, a three-carbon compound, is the primary CO₂ acceptor... 1
- Which one of the following plants does not show plasticity ? Answer: 1. Maize Plasticity means a plant shows different forms in response to environment or life phase, such as heterophylly. Cotton, cori... 1
- What amount of energy is released from glucose during lactic acid fermentation ? Answer: 1. Less than 7% Lactic acid fermentation releases less than 7% of the energy in glucose. Most energy stays in the lactic acid, since... 1
- What is the net gain of ATP when each molecule of glucose is converted to two molecules of pyruvic acid ? Answer: 4. Two In glycolysis, one glucose gives two pyruvic acid molecules. 4 ATP are made and 2 ATP are used in the preparatory steps, so t... 1
- Which one of the following is not true regarding the release of energy during ATP synthesis through chemiosmosis ? It involves : Answer: 3. Breakdown of electron gradient In chemiosmosis, a proton gradient (not an electron gradient) drives ATP synthesis. Protons move a... 1
- Production of Cucumber has increased manifold in recent years. Application of which of the following phytohormones has resulted in this increased yield as the hormone is known to produce female flowers in the plants : Answer: 4. Ethylene Ethylene promotes female flowers in cucumber, which increases fruit yield. Gibberellins in cucumber tend to promote male... 1
- The gaseous plant growth regulator is used in plants to : Answer: 3. promote root growth and roothair formation to increase the absorption surface The gaseous plant growth regulator is ethylene. It... 1
- Match List - I with List - II.List - I: (a) Manganese (b) Magnesium (c) Boron (d) IronList - II: (i) Activates the enzyme catalase (ii) Required for pollen germination (iii) Activates enzymes of respiration (iv) Functions in splitting of water during… Answer: 3. (a) - (iv), (b) - (iii), (c) - (ii), (d) - (i) Manganese functions in splitting of water in photosynthesis: (a)-(iv). Magnesium a... 1
- Which of the following statements is incorrect ? Answer: 4. Cyclic photophosphorylation involves both PS I and PS II. Find the incorrect statement. Cyclic photophosphorylation involves only... 1
- Match Column - I with Column - II.Column - I | Column - II(a) Nitrococcus | (i) Denitrification(b) Rhizobium | (ii) Conversion of ammonia to nitrite(c) Thiobacillus | (iii) Conversion of nitrite to nitrate(d) Nitrobacter | (iv) Conversion of atmosphe… Answer: 1. (a)-(ii), (b)-(iv), (c)-(i), (d)-(iii) Match each bacterium with its role: Nitrococcus converts ammonia to nitrite: (a)-(ii). Rhi... 1
- Which of the following statements is incorrect ? Answer: 2. In ETC (Electron Transport Chain), one molecule of NADH+H ^+ gives rise to 2 ATP molecules, and one FADH ₂ gives rise to 3 ATP mo... 1
- Match List - I with List - II.List - I | List - II(a) Cohesion | (i) More attraction in liquid phase(b) Adhesion | (ii) Mutual attraction among water molecules(c) Surface tension | (iii) Water loss in liquid phase(d) Guttation | (iv) Attraction towar… Answer: 1. (a)-(ii), (b)-(iv), (c)-(i), (d)-(iii) Match the terms with their meanings: Cohesion is mutual attraction among water molecules:... 1
- The first stable product of CO_2 fixation in sorghum is : Answer: 2. Oxaloacetic acid Sorghum is a C4 plant. Its mesophyll cells fix CO ₂ with PEP carboxylase, so the first stable product is a 4-car... 1
- Plants follow different pathways in response to environment or phases of life to form different kinds of structures. This ability is called : Answer: 3. Plasticity The ability of a plant to form different structures in response to its environment or its phase of life is called plas... 1
- The site of perception of light in plants during photoperiodism is : Answer: 4. Leaf In photoperiodism the stimulus is perceived by the leaves. A leaf exposed to the right photoperiod can send a flowering sign... 1
- The plant hormone used to destroy weeds in a field is : Answer: 3. 2, 4-D 2,4-D is a synthetic auxin that kills dicot weeds without harming monocot crops such as wheat and maize. IAA, NAA and IBA... 1
- The number of substrate level phosphorylations in one turn of citric acid cycle is : Answer: 2. One In one turn of the citric acid cycle, one substrate level phosphorylation occurs: succinyl-CoA to succinate, forming GTP (whi... 1
- In light reaction, plastoquinone facilitates the transfer of electrons from : Answer: 1. PS-II to Cytb ₆ f complex In the Z-scheme, electrons from PS II go to plastoquinone (PQ), then to the Cyt b6f complex, then plast... 1
- Name the plant growth regulator which upon spraying on sugarcane crop, increases the length of stem, thus increasing the yield of sugarcane crop. Answer: 2. Gibberellin Gibberellin promotes stem elongation (internode length). Spraying it on sugarcane raises stem length and hence yield... 1
- Which of the following is not an inhibitory substance governing seed dormancy ? Answer: 1. Gibberellic acid Seed dormancy is maintained by inhibitors such as abscisic acid, phenolic acids and para-ascorbic acid. Gibberel... 1