The mean photosynthetic rates of $C_3$ and $C_4$ plants per $dm^2$ per hour are respectively:

Analogy type question:
$(1)$ Biosynthetic phase : Based on $CO_2$ and $H_2O$ :: Phosphorylation : ......
$(2)$ First product of $C_3$ cycle : $PGA$ :: First product of $C_4$ cycle : ......

For photosynthesis (i.e. for the synthesis of organic matter),the green plants need only

During daylight hours,the rate of photosynthesis is higher than the rate of respiration,and the ratio of oxygen produced to oxygen consumed is ......... . (in $:1$)

Assertion $:-$ There is not a complete one-to-one overlap between the absorption spectrum of chlorophyll $a$ and the action spectrum of photosynthesis.
Reason $:$ Most of the photosynthesis takes place in the blue and red regions of the spectrum,but some photosynthesis does take place at the other wavelengths of the visible spectrum.

Choose the correct sentence$(s)$ from the following:
$(i).$ In $C_4$ plants,the first $CO_2$ acceptor is $PEP$.
$(ii).$ Light energy is absorbed by $PS-II$ at $680 \ nm$ in the process of photosynthesis.
$(iii).$ The $P_{680}$ chlorophyll system is present in $PS-I$.