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

In which of the following is oxygen $NOT$ produced during photosynthesis?

Which of the following statements with regard to photosynthesis is/are correct?
$I$. In $C_{4}$-plants,the primary $CO_{2}$ acceptor is $PEP$.
$II$. In the photosynthetic process,$PS-II$ absorbs energy at or just below $680 \;nm$.
$III$. The pigment that is present in the Pigment System-$I$ is $P680$.

The green part of the plant is primarily involved in which of the following processes?

Assertion: Photosynthetically,$C_4$ plants are less efficient than $C_3$ plants.
Reason: The operation of the $C_4$ pathway requires the involvement of only bundle-sheath cells.

'Sun basket' is