By observing the chloroplasts in a leaf, the students learn that plants produce their own food and do not get it from another source. The students come to the conclusion that the chloroplasts use sunlight, air, and water to create sugar, which is used as energy for the plant.
Ms. Frizzle and her class learn about vibrations and sound by playing with instruments and hitting objects. They not only hear and feel sound but see it using special glasses. Among many other lessons, they learn that high sounds are created by a fast vibration and low sounds are created by a slow vibration.
Tim mentions to Inspector 47 that all of the plants, animals, bugs, and insects in the rainforest are connected in many ways. He explains how they are ecologically interdependent on each other for food and habitats.