Answer:
The sun
Step-by-step explanation:
The sun is the only star in our solar system. It provides the ultimate source of energy for all parts of an ecosystem.
Light energy from the sun is used to drive photosynthetic processes. This process in turn provides food for all organism.
The energy of the sun is produced from the fusion of hydrogen nuclides at great temperatures within the sun. The fusion process releases the energy which every part of the solar system needs.