Final answer:
Plants produce the sugars required for respiration through the process of photosynthesis, where carbon dioxide, water, and sunlight are converted into glucose and oxygen. Oxygen is also released during photosynthesis and is used in cellular respiration. Water and minerals absorbed from soil through the roots support these processes.
Step-by-step explanation:
Plants obtain the raw materials needed for respiration through two main processes: photosynthesis and nutrient absorption. During photosynthesis, plants convert carbon dioxide and water into glucose (a sugar) and oxygen using the energy from sunlight. This reaction can be summarized as 6CO₂(g) + 6H₂O(l) → C₆H₁₂O₆(s) + 6O₂(g). The glucose produced provides the necessary sugars for respiration, while the oxygen that is released is a by-product of this process and also serves as the oxidizing agent during cellular respiration. Additionally, plants take up water and mineral nutrients through their roots from the soil, which are also crucial for the production of glucose in photosynthesis and other cellular functions.