Question

Why is it usually difficult to demonstrate respiration in green plants?

Answer 1

This is because in plants $C{O}_2$ is released during respiration but at the same time respiration also occurs in which the $C{O}_2$ which was released is consumed by the plant itself. Hence it is difficult to demonstrate respiration in green plants during the daytime but it is easy to demonstrate the process of respiration during the night because at night no photosynthesis occurs in plants.