Which term describes organisms that synthesize their own food from inorganic sources using light or chemical energy?

• A. Heterotroph
• B. Decomposer
• C. Autotroph
• D. Producer

Answer: (C)

Autotrophs are organisms that make their own organic matter from inorganic inputs, using energy from light or from chemical reactions. This means they don’t need to eat other organisms to obtain carbon and energy. In plants, algae, and photoautotrophic bacteria, sunlight drives the synthesis of sugars through photosynthesis. In some bacteria, chemical energy from inorganic substances drives a similar process called chemosynthesis. Because they build the biomass that starts most food chains, autotrophs are the primary producers in ecosystems.

Heterotrophs, by contrast, must obtain organic carbon by consuming others, and decomposers are a subset of heterotrophs that break down dead material. While “producer” is related—a producer is typically an autotroph—the precise scientific term for the trait described is autotroph.