Final answer:
The sun plays a crucial role as the ultimate source of energy for almost all cells. It enables plants to produce glucose through photosynthesis, provides warmth through solar radiation, and powers cellular respiration through sunlight.
Step-by-step explanation:
The sun plays a crucial role as the ultimate source of energy for almost all cells. This is because of photosynthesis in plants, solar radiation providing warmth, and the sunlight powering cellular respiration. Photosynthesis in plants enables them to convert solar energy into chemical energy in the form of glucose, which is used as food by plants and other organisms. Solar radiation from the sun provides warmth, which is essential for the survival and metabolism of organisms. Finally, sunlight powers cellular respiration, a process in which cells convert glucose and oxygen into ATP, the energy currency of cells.