Which term describes organisms that obtain energy by consuming organic compounds produced by others?

• A. Photoautotrophs
• B. Chemoautotrophs
• C. Heterotrophs
• D. Autotrophs

Answer: (C)

Organisms that obtain energy by consuming organic compounds produced by other organisms are heterotrophs. They rely on preformed organic molecules for both carbon and energy, meaning they must ingest or absorb nutrients like sugars, fats, and proteins rather than making them from inorganic sources. The energy comes from breaking these organic molecules down through processes like cellular respiration or fermentation. This is different from autotrophs, which generate their own organic matter from inorganic carbon sources—photoautotrophs using light and chemoautotrophs using chemical energy to build those molecules. Heterotrophs include animals, fungi, many bacteria, and various protists, spanning consumers and decomposers.