$DCMU$ ($3$-($3$,$4$-dichlorophenyl)$-1,1-$dimethylurea) is a chemical that acts as an inhibitor of photosynthesis. What is its specific mode of action?

The reaction centres for $PS-I$ and $PS-II$ are

Who is the primary electron acceptor in $Photosystem-I$ $(PS-I)$?

The important function of $PS-II$ in photosynthesis is .........

The following $(I-VI)$ are the main steps of chemiosmotic $ATP$ synthesis in the light reaction. Arrange them in the correct order:
$I$. $H^+$ concentration gradient established
$II$. $H^+$ diffuses through $ATP$ synthase
$III$. Carriers use energy from electrons to move $H^+$ across the membrane
$IV$. Electrons from $PS-II$ pass along the electron transport chain
$V$. Light excites electrons in $PS-II$
$VI$. Energy of $H^+$ flow is used by $ATP$ synthase to make $ATP$

The entire process of photosynthesis consists of a number of reactions. Where in the cell do each of these take place? Photolysis of water ...........