How is an organism’s energy role determined? An organism’s energy role is determined by how it obtains energy and how it interacts with other organisms. EX: (your experience, new question, or WU answered.) Each of the organisms in an ecosystem fills the energy role of producer, consumer, or decomposer.

What is a producer? An organism that can produce its own food. Plants, algae, and some bacteria capture the energy of sunlight and store it as food. Producers are the source of all food in an ecosystem. EX: (your experience, new question, or WU answered.) Exception: In rocks deep beneath the ground, there is a bacteria can produce their own food using a gas called hydrogen sulfide.

What is a consumer? An organism that obtains energy by feeding on other organisms Classified by what they eat: Herbivores-eat plants Carnivores-eat meat Omnivores-eat both Scavengers-dead organisms

What is a decomposer? Nature’s recyclers: break down wastes and dead organisms and return simple molecules to the ecosystem. EX: (your experience, new question, or WU answered.)

What is a food chain? Series of events in which one organism eats another and obtains energy. EX: (your experience, new question, or WU answered.)

What is a food web? Many overlapping food chains in an ecosystem. EX: (your experience, new question, or WU answered.)

Food Chains and Food Webs Please turn to page 743 in your textbooks and study the consumer levels.