B(4-2) How do organisms get energy? Vocabulary producer food chain consumer food web energy pyramid Copyright © Houghton Mifflin Harcourt Publishing Company

Getting Energy The transfer of food energy from one organism to the next in an ecosystem is called a food chain. Almost every food chain begins when producers capture energy from the sun. Through photosynthesis, producers convert this light energy into chemical energy in sugars, which they use for food. Copyright © Houghton Mifflin Harcourt Publishing Company

Getting Energy Food not used for life processes is stored in producers’ tissues and passed to herbivores that eat producers. Herbivores are primary consumers. Carnivores and omnivores, secondary consumers, eat herbivores and receive the food energy stored in their bodies. Copyright © Houghton Mifflin Harcourt Publishing Company

Getting Energy Ecosystems also have have decomposers and scavengers. Scavengers, such as vultures, are consumers, as they eat dead organisms. Decomposers, the last level in a food chain, break down the remains of dead plants and animals for energy and return nutrients to the soil. Copyright © Houghton Mifflin Harcourt Publishing Company

Food Webs Each consumer has a variety of choices when it comes to its next meal. A food web is a group of connected food chains in an ecosystem. For example, a bear can eat a chipmunk or a deer. Eventually, these living things become food for decomposers. Copyright © Houghton Mifflin Harcourt Publishing Company

Food Webs Decomposers return nutrients to soil. These nutrients, in turn, are used by producers to make food. Arrows in a food web point in the direction that energy moves. Predators limit the number of animals below them in a food web. All of the organisms in a food web are interdependent. Copyright © Houghton Mifflin Harcourt Publishing Company

Food Webs How many different food chains does this food web contain? Copyright © Houghton Mifflin Harcourt Publishing Company

The energy pyramid When the butterfly eat plants, the butterfly gets the energy that was stored in the plant. The butterfly uses some of the energy to move and grow. Some of the energy in the plant can't be used by the butterfly. it's lost from the food chain as waste heat. This heat is the result of bodily and chemical processes. The rest of the energy is stored in the butterfly's body. Copyright © Houghton Mifflin Harcourt Publishing Company

The Energy Pyramid An energy pyramid shows that the energy is lost at each level of the food chain. Because of this energy loss, the number of organisms decreases from one level to the next. Copyright © Houghton Mifflin Harcourt Publishing Company

The energy pyramid Environmental changes can affect energy flow in an energy pyramid. Whatever happens at one level affects the energy in the rest of the pyramid. Copyright © Houghton Mifflin Harcourt Publishing Company

The energy pyramid How much energy is lost with each step up? How much of the energy of the bamboo plants is lost by the third step of the pyramid?