Photosystem $II$ occurs in a

Which element is present in the $OEC$ (Oxygen Evolving Complex)?

How many quanta of light are required to evolve one molecule of $O_2$ during photosynthesis in green plants?

$ATP$ synthesis in chloroplasts and mitochondria is due to a proton gradient across the membrane. Select the correct statements with respect to $ATP$ formation in chloroplasts:
$(a)$ Protons accumulate in the lumen of the thylakoid.
$(b)$ Splitting of water occurs on the inner side of the membrane.
$(c)$ Protons accumulate on the stroma side of the chloroplast.
$(d)$ $NADP$ reductase is located on the stroma side of the membrane.

$PS-I$ is located on the

Stroma lamellae membrane lacks:
$I. PS-II$
$II. NADP$ reductase
$III. \text{non-cyclic photophosphorylation}$
Select the correct option.