Photosynthesis cannot continue for long if during light reaction , only cyclic photophosphorylation takes place. This is because

Options

A. only ATP is formed `NADPH^(+) +H^(+)` is not formed
B. photosystem -I stops getting excited at a wavelength of light beyond 680 nm
C. there is unidirectional cyclic movement of the electrons
D. there is no evolution of `O_2`

Answer

A

Explanation

Assimilatory power.i.e, ATP and `NADPH_2` are produced during light reaction pf photosynthesis . As only cyclic photophosphorylation takes place , only ATP is formed and photosynthesis cannot continue for long . Because in the absence of `NADPH_2` the dark reaction of photosynthesis does not take place.