Question

III. Sometimes the plant act as a closed system in terms of gas exchange. How?

Answer 1

Gas Exchange in Plants. Plants obtain the gases they need through their leaves. They require oxygen for respiration and carbon dioxide for photosynthesis. The gases diffuse into the intercellular spaces of the leaf through pores, which are normally on the underside of the leaf - stomata.

Answer 2

Plants respire all the time, but photosynthesis only happens during the day. This means that the net gas exchange from a leaf depends on the light intensity.