Which energy source do producers primarily use to make food?

• A. Kinetic energy
• B. Nuclear energy in sunlight
• C. Chemical energy
• D. Light energy

Answer: (D)

Producers make food by turning light energy into chemical energy through photosynthesis. Chlorophyll in plants absorbs light and uses that energy to drive reactions that convert carbon dioxide and water into glucose, storing energy in the chemical bonds of the sugar. In other words, light energy is the input that powers the process, and the result is chemical energy stored in the food molecules.

Kinetic energy is just moving energy, so it isn’t what starts photosynthesis. The energy stored in glucose is chemical energy, which is the output of the process, not the input. While sunlight comes from nuclear fusion in the sun, what plants directly use to power photosynthesis is light energy arriving on Earth.