By looking at a plant externally, can you tell whether it is ${ C }{ 3 }$or
${ C }{ 4 }$ ? Why and how?
The plants which are adapted to dry tropical regions have the ${ C }{ 4 }$ pathway. However, the
${ C }{ 4 }$-plants do not show any characteristic in external morphology. Therefore, it is difficult to say whether a plant is
${ C }{ 3 }$ or
${ C }{ 4 }$by looking it only externally.