Mention important matters for $C_4$ plants.

(N/A) In $C_4$ plants,photorespiration does not occur.
This is because they possess a mechanism that increases the concentration of $CO_2$ at the enzyme site.
This occurs when the $C_4$ acid from the mesophyll cells is broken down in the bundle sheath cells to release $CO_2$.
This process results in increasing the intracellular concentration of $CO_2$.
In turn,this ensures that the $RuBisCO$ enzyme functions primarily as a carboxylase,thereby minimizing its oxygenase activity.
Consequently,the productivity of $C_4$ plants is significantly higher than that of $C_3$ plants.