Where is your source of energy for your living things?

Answer 1

Energy begins with the sun. Autotrophic organisms use sunlight (among other nutrients) to produce their own food. Then other organisms eat them and use their energy.

However, the more times the energy is passed up the food chain, the more energy is lost. That is one reason why it so so important to eat fruits and vegetables, because their plants are primary producers and their energy has not been lost through the food chain yet.