1. Roles of Living Things Chapter 4 Section 1

2. Organisms that make their own food from inorganic molecules and energy are called producers. –Plants are the most important producers in terrestrial ecosystems. –In aquatic ecosystems, small photosynthetic protists and bacteria are the most important producers.

3. Organisms that cannot make their own food are called consumers. –Organisms that eat only plants are called consumers. (Primary consumers) –Organisms that eat only meat called carnivores. (Secondary consumers) –Organisms that eat both plants and animals are called omnivores (Can act as primary, secondary, and tertiary consumers) –Organisms that feed of the bodies of dead organisms are called scavengers.

4. Bacteria and fungi that consume the bodies of dead organisms and other organic wastes are called decomposers. Decomposers recycle nutrients from organisms back into the environment. A trophic level is a layer in the structure of feeding relationships in an ecosystem. Producers are called autotrophs because they make their own food. Consumers are called heterotrophs because they eat other organisms.