The correlation between 'Kranz' anatomy and the $C_4$ pathway of $CO_2$ assimilation was first established by:

Site of $C_3$ cycle in $C_4$ plants is $:-$

In $CAM$ plants,the source of $CO_2$ for photosynthesis during the day is . . . . . . .

Kranz anatomy is found in ............

The $C_{4}$ plants are twice as efficient as $C_{3}$ plants in terms of fixing $CO_{2}$ but lose only $........$ as much water as $C_{3}$ plants for the same amount of $CO_{2}$ fixed.

In which type of plants do the stomata remain closed during the daytime and open during the night?