The mechanism of $ATP$ formation both in chloroplast and mitochondria is explained by

Assertion $(A) :-$ The whole scheme of transfer of electrons starting from $PS-II$ to $NADP^{+}$ is called $Z-scheme$.
Reason $(R) :-$ When all the carriers of this scheme are placed in sequence on a redox potential scale,they appear like $Z$.
In the light of the above statements,choose the correct answer from the options given below:

Provide definitions/explanations for the following terms:
$(1)$ Photosynthesis
$(2)$ Light reaction

The separation of water into hydrogen and oxygen during photosynthesis is aided by

In the grana of the chloroplast,the reaction $ADP + \Pi = ATP$ during the day shows:

During the light reaction,the water splits into