Which term describes an organism that is unable to produce its own food?

The term that describes an organism unable to produce its own food is indeed heterotroph. Heterotrophs obtain their nutrients and energy by consuming other organisms or organic matter. This category includes animals, fungi, and many bacteria, all of which rely on autotrophs (organisms that can produce their own food through processes like photosynthesis) or other heterotrophs for sustenance.

Understanding the distinction between heterotrophs and other types of organisms is key in ecology. Autotrophs, in contrast, are capable of converting inorganic substances into organic matter. Producers are synonymous with autotrophs, functioning at the base of the food chain by creating energy-rich compounds that serve as food for heterotrophs. Decomposers break down dead organic material, recycling nutrients into the ecosystem. By recognizing these roles, one can appreciate the intricate dynamics of energy transfer within ecological communities.