Which of the following is the most abundant protein in the chloroplast?

The balance between $CO_2$ and $O_2$ in the atmosphere is maintained by:

How many molecules of water are needed by a green plant to produce one molecule of hexose or to reduce $6$ molecules of $CO_2$?

Which of the following evidence indicates that the oxygen released during photosynthesis is derived from water?

Match the following columns correctly:

Column-$I$	Column-$II$
$(1)$ Cyclic photophosphorylation	$(a)$ Only $PS-I$
$(2)$ Non-cyclic photophosphorylation	$(b)$ $ATP$ formed
$(3)$ $C_4$ cycle	$(c)$ Meristematic tissue
	$(d)$ High productivity

$I.$ Initial $CO_{2}$ acceptor
$II.$ Extent of photorespiration
$III.$ Enzyme catalyzing reaction that fixes $CO_{2}$
$IV.$ Presence of Calvin cycle
$V.$ Leaf anatomy
Which one does not differ in a $C_{3}$ and $C_{4}$ plant?