Question

`O_(2)` evotution is directly associated with
Or
Which of the following does not participates when the light reaction synthesizes only ATP or performs the cyclic flow of electrons
A. PS-I
B. PS-II
C. Phytochrome
D. Phycocyanin

Answer 1

Correct Answer - B
The photosystem-II (reaction centre of _680) extracts an `e^(-)` from water returning to its unexcited state. The removal of four `e^(-)` from two molecules of water requires 4 quanta of light to fall on PS-II and leads to the production of `4H^(+)` ions and one molecules of `O_(2)`.