Which was the first stable product in the light-dependent reaction of $C_4$ plants?

In the leaves of $C_4$ plants,in which cells does the formation of malic acid occur during $CO_2$ fixation?

Which of the following is not correct for $C_4$ plants?

Even though a very few cells in a $C_{4}$ plant carry out the biosynthetic-Calvin pathway,yet they are highly productive. Can you discuss why?

The $C_{4}$-plants are photosynthetically more efficient than $C_{3}$-plants because

In Hatch and Slack pathway,