The question that would best help explain how photosynthesis and cellular respiration are connected is:
"Do photosynthesis and cellular respiration convert the same materials?"
This question directly relates to the relationship between the two processes, highlighting how the reactants of one process function as the products of the other. Photosynthesis converts carbon dioxide and water into glucose and oxygen, while cellular respiration uses glucose and oxygen to produce carbon dioxide and water, thereby illustrating a cyclical connection between the two processes.