Final answer:
All living organisms on Earth use solar energy to sustain themselves through the process of photosynthesis. Solar energy is converted into chemical energy in the form of carbohydrate molecules, which cells use for various functions.
Step-by-step explanation:
All living organisms on Earth use solar energy to sustain themselves. Through the process of photosynthesis, certain organisms convert solar energy into chemical energy in the form of carbohydrate molecules. This energy is then used by cells to perform various functions, such as movement or growth. Ultimately, solar energy is the primary source of energy for all living things on Earth.