GK
SOIL AND AGRICULTURE
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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CMU and DCMU
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2, 4-Dinitrophenol
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None of these
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Detailed explanation-1: -Complete step by step answer: DCMU only blocks photosystem II electron flow; it has no effect on photosystem I or other photosynthesis reactions, such as light absorption or Calvin cycle carbon fixation. . DCMU is a photophosphorylation inhibitor.
Detailed explanation-2: -DCMU kills the weed by inhibition of carbon dioxide fixation, as it is a strong inhibitor of photosystem-II. DCMU acts by blocking electron flow at the guanine acceptors of PS-II (water-plastoquinone oxidoreductase) pigment or pigment system, by attaching itself with the binding site called plastoquinone.
Detailed explanation-3: -Valinomycin and 2, 4-dinitrophenol also inhibit photosystem II cyclic photophosphorylation, but these compounds appear to act as electron transport inhibitors rather than as uncouplers.