The source of $O_2$ liberated in photosynthesis in green plants is:

Read the following statements:
$(a)$ $F_{0}$ part of $ATP$ase is associated with the breakdown of the proton gradient.
$(b)$ $A$ $H^+$ carrier contributes to the creation of the proton gradient.
$(c)$ Movement of electrons in $ETS$ is coupled to the pumping of protons into the lumen.
$(d)$ Formation of $NADPH + H^+$ is related to the creation of the proton gradient.
How many of the above statements are correct?

Which one of the following is not true about the light reactions of photosynthesis?

The minerals involved in the photolysis of water are:
$I$ Manganese
$II$ Calcium
$III$ Magnesium
$IV$ Chloride

Which of the following conditions are favourable for cyclic photophosphorylation?

The first step in photosynthesis is