Photosynthesis is the process plants use to convert sunlight into chemical energy. The process of photosynthesis can be modeled to illustrate the most important aspects of the natural phenomenon. Through this process, plants use energy in sunlight to turn carbon dioxide gas and water into sugar. Plants then use this sugar to grow. At the same time, plants produce oxygen gas as a waste product which animals breathe. Read the prompt and study the diagram. What cause and effect prediction can be used to test the assumptions in the model?