Question

The herbicide DCMU kills the weeds because it inhibits
A. respiration
B. `CO_(2)` fixation
C. cell division
D. `NO_(3)^(2-)` uptake

Answer 1

Correct Answer - B
DCMU (Dichlorophenyl urea) is a herbicide which kills the weeds by inhibiting `CO_(2)` fixation as it is a strong inhibitor of photosystem II `(P_(680))` DCMU acts by blocking electron flow at the guanine acceptors of PS II, by competing for the binding site of plastoquinone.