Dude i think it the calven cycle
The three colors of cellophane serves as the light source for the set-up. The three colors would give different wavelengths of light to the sample in the jar. It is the independent variable in this experiment. Hope this answers the question.
They are part of the stomatal can be found in the skin of the leaf and stem. Guard cells have characteristic shapes can be bean-shaped or like sponge cake. They have thickened cell walls contain living protoplasm of chloroplasts (as opposed to skin cells)
