How do organisms obtain energy? Sunlight is the main energy source for life on Earth. An organism’s energy role in an ecosystem is determined by how it obtains energy. (contd.)

Producers are plants that use the sun’s energy in making food. Consumers eat plants or other animals. Consumers include herbivores, carnivores, and scavengers. 1. Identify Which group of organisms in an ecosystem provides energy for all the others? (contd.)

Decomposers digest the waste and remains of dead plants and animals.

What are food chains and food webs? The movement of energy through ecosystems is shown in diagrams called food chains and food webs. In a food chain, organisms transfer energy by eating and being eaten. (contd.)

A food chain always begins with energy from sunlight to producers. Energy flows through a food chain in one direction. 2. Describe Describe the flow of energy in the food chain shown to the left. (contd.)

A system of overlapping food chains is called a food web A system of overlapping food chains is called a food web. In a food web, the flow of energy branches out in many directions. 3. Interpret Visuals How could you draw arrows to show how the decomposers are related to the other organisms in the food web?

What is an energy pyramid? An energy pyramid shows how energy moves through an ecosystem. The base of the energy pyramid is wider because more food energy is available. Only stored energy can pass along the food chain. Less energy flows upward from the lower levels to the higher ones. 4. Infer Why does the number of animals decrease the higher they are on the food pyramid? (contd.)