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49. Primary acceptor of CO2 in photosynthesis is (1) Ribose                                          (2) Ribulose-5-P (3) Ribulose1,5-bis Phosphate           (4) 3-Phosphoglycerate The correct answer is (3): Ribulose-1,5-bisphosphate. In C3 photosynthesis (Calvin cycle), the […]

48. Which protein subunit of RUBICO is coded by chloroplast genome? (1) Small sub-unit of RUBISCO (2) Large sub-unit of RUBISCO (3) Entire RUBISCO (4) none The correct answer is […]

47. ‘A’ is an inhibitor of chloroplast function. The production of O2 and synthesis of ATP are measured in illuminated chloroplast before and after addition of ‘A’ as shown below. […]

46. In an experiment, spinach chloroplast are illuminated in the absence of ADP and Pi, then the light is turned off and ADP and Pi are added. Identify the correct […]

A researcher wanted to study light reaction during photosynthesis by blocking photosynthetic electron flow using the herbicide, di-chloro-phenyl-dimethyl-urea (DCMU) and paraquat. The researcher listed the following observations: A. Both DCMU […]

44. The one of the most widely used herbicides methyl viologens (paraquat) interfere photosynthesis of higher plants. They are responsible for (1) Evolution of more oxygen (2) Dissipation of proton […]

43. Identify the correct site of action of DBMIB (2,5-dibromo-3-methyl-6-isopropyl-p-benzoquinone), an inhibitor of the chloroplast electron transport chain. (1)QA —àQB                (2) QB —àPQ’ (3) PQ —àCytb6 f         (4) […]

42. The herbicide, dichlorophenyldi-methylurea (DCMU), is an inhibitor of (1) Shikimate pathway for biosynthesis of aromatic amino acids. (2) Electron transport from P680 to P700. (3) Branch in amino acid […]

41. Dichlorophenyl dimethyl urea       (DCMU) inhibits photosynthesis at which step? (1) phe–àQA                          (2) QA–àQB (3) Cyt bf6–àPC                       (4) QB–àCytbf6 DCMU inhibits photosynthesis at the step (2) QA → […]

DCMU inhibits electron transport in chloroplast by preventing the reduction of (1) P680. (2) QA. (3) PQ. (4) QB DCMU inhibits electron transport in chloroplasts by preventing the reduction of […]