Biology STAAR (State of Texas Assessments of Academic Readiness) Practice Test

Which term refers to organisms that feed on other organisms?

1. Autotrophs

2. Heterotrophs

3. Producers

4. Decomposers

The correct answer is: Heterotrophs

Heterotrophs are organisms that obtain their nutrients and energy by consuming other organisms, which can include plants, animals, and microorganisms. This group encompasses a wide variety of life forms, including herbivores, carnivores, and omnivores. By relying on other organisms for food, heterotrophs play a crucial role in the ecosystem's food web and contribute to energy transfer. The distinction between heterotrophs and other types of organisms, like autotrophs, is important. Autotrophs, unlike heterotrophs, are able to produce their own food through processes like photosynthesis and chemosynthesis, using carbon dioxide and sunlight or inorganic molecules as energy sources. Producers, which primarily refer to autotrophs in the food chain, are crucial for creating organic matter that supports all other types of life. Decomposers, such as fungi and bacteria, break down dead organic material and recycle nutrients back into the ecosystem. While they also consume other organisms (specifically dead ones), their role is more about decomposition and nutrient cycling rather than the direct feeding off living organisms. Thus, the term heterotrophs accurately describes organisms that rely on consuming others for energy and nutrients.