Leaves fall off the tree in the autumn, but why do they change colors? The interactive covers the role of chlorophyll and photosynthesis. It also explains both carotenoids and anthocyanins.

Yes, Venn diagrams are helpful in science, too. Learners use an interactive to classify celestial bodies as having moons, as dwarf plants, as both, or as neither. They answer a set of challenge questions based on the Venn diagrams they...

Cellular respiration and photosynthesis relate closely, but many don't realize how. Scholars drag and drop the reactants and products to the chemical reactions for both processes. Then they answer three multiple-choice questions.