During the formation of glucose,which of the following is obtained from water?

The oxygen evolved during photosynthesis comes from water molecules. Which one of the following pairs of elements is involved in this reaction?

Which of the following is associated with the transfer of electrons in photosynthesis?

Read the following four statements,$(i), (ii), (iii)$ and $(iv)$ and select the right option having both correct statements.
Statements:
$(i)$ $Z$ scheme of light reaction takes place in the presence of $PSI$ only.
$(ii)$ Only $PSI$ is functional in cyclic photophosphorylation.
$(iii)$ Cyclic photophosphorylation results in the synthesis of $ATP$ and $NADPH_2$.
$(iv)$ Stroma lamellae lack $PSII$ as well as $NADP$ reductase.

The Emerson enhancement effect and the red drop phenomenon were instrumental in the discovery of which of the following?

How many molecules of water should be photolysed to form one $NADPH_2$ molecule?