Final answer:
Plants take in carbon dioxide and water for photosynthesis and use oxygen for cellular respiration. The products of photosynthesis serve as the reactants in cellular respiration, forming a cycle between these two processes.
Step-by-step explanation:
Plants require specific inputs to carry out the processes of photosynthesis and cellular respiration. For photosynthesis, plants take in carbon dioxide (CO₂) from the air and water (H₂O) to produce carbohydrates, such as glucose, and release oxygen (O₂) as a by-product. During cellular respiration, plants use oxygen (O₂) to break down glucose to produce energy in the form of ATP, releasing carbon dioxide (CO₂) and water (H₂O) as waste products. This demonstrates a cycle where the oxygen released during photosynthesis is used in cellular respiration, and the carbon dioxide released during cellular respiration is used in photosynthesis.