Energy Flow in Ecosystems Energy Roles Energy enters most ecosystems as radiant energy. Energy moves through an ecosystem. Each organism in an ecosystem plays a part in the movement of energy. An organism that can make its own food is called a producer. An organism that gets its energy by eating other organisms is called a consumer. Herbivores are consumers that eat only plants. Carnivores are consumers that eat only animals. Omnivores are consumers that eat both plants and animals. An organism that gets energy by eating wastes and dead organisms is called a decomposer. Mushrooms and bacteria are decomposers. 1. Energy enters most ecosystems as radiant energy from the sun. 2. Select the correct term for each definition. TERM MEANING A. Decomposer B.an organism that makes its own food B. Producer C.an organism that gets energy by eating other organisms C. Consumer A.an organism that gets energy by eating wastes or dead organisms 3. Select the correct term for each description. TERM DESCRIPTION A. Carnivore A. consumer that eats only animals B. Herbivore C. consumer that eats both plants and animals C. Omnivore B. consumer that eats only plants Food Chains and Food Webs The movement of energy through an ecosystem can be shown in diagrams called food chains and food webs. Food chains and food webs are diagrams. They show how energy moves through an ecosystem. A food chain shows a series of organisms that eat other organisms. The first organism in a food chain is always a producer. The organism that eats the producer is called a first-level consumer. The organism that eats the first-level consumer is called a second-level consumer. A food web is made up of many food chains in an ecosystem. The food chains overlap and connect with one another.
4. A diagram that shows a series of organisms that eat other organisms is called a(n) food chain. 5. A diagram that is made up of many food chains is called a(n) food web. 6. The picture below shows a food chain. In this food chain, there is a producer, a firstlevel consumer, second-level consumer, and a decomposer. 7. Name the organism that eats only plants rabbit. 8. Name the organism that eats only meat. owl 9. Name the organism that breaks down decaying matter. Mushroom (decomposer; fungus) 10. The sun provides radiant energy. Energy Pyramids In an energy pyramid, the most energy is available at the producer level of the pyramid. As you move up the pyramid, each level has less energy available than the level below. An energy pyramid is a diagram in the shape of a pyramid. It shows how much energy moves from one feeding level to another. Energy moves from the bottom level up to the top level. The first level of an energy pyramid always has the most energy. Each level of an energy pyramid has less energy than the level below it.
11. Circle the letter of the name of a diagram that shows how much energy moves from one feeding level to another. a. food web b. energy pyramid c. food chain 12. Circle the letter of each sentence that is true about energy pyramids. a. Energy moves from the bottom level to the top level. b. The first level always has the most energy. c. Each level has more energy than the level below it. 13. How much energy is passed on from one energy level to the next? a. 90% b. 50% c. 10% 14. How much energy is USED from one energy level to the next? a. 90% (used for body processes) b. 50% c. 10%
Food Webs Organisms need a habitat that provides food, water, space, and a place to reproduce. Food webs are a complex system of energy flow through overlapping food chains. In a food web, arrows point in the direction that energy flows. Energy begins with the sun to the plants (producers) to the primary consumers and then to the secondary consumers. 15. When a rabbit eats grass, what form of energy passes directly from the grass to the rabbit? a. heat c. chemical b. light d. electrical 16. In the food web above, which is a primary consumer? a. hawk b. toad c. fox d. mouse 17. In the food web above, which of the following consumers feeds on the largest variety of different organisms? a. fox c. toad b. spider d. squirrel
18. Grass Rabbit Fox Which statement best describes a likely relationship between the organisms in the food chain shown above? a. If the rabbit population decreases, the fox population will increase. b. If the grass population decreases, the fox population will remain the same. c. If the rabbit population increases, the grass population will increase. d. If the grass population increases, both the rabbit and fox populations will increase. 19. Plants Spiders Hawks What is the original source of energy for all the organisms in the food chain above? a. soil particles b. carbon dioxide c. sunlight (radiant energy) d. oxygen 20. In a grassland community, grasses are considered a. secondary consumers b. primary consumers c. decomposers d. producers 21. The fungi shown in the picture above are decomposers. Decomposers are an important part of an ecosystem because they --- a. produce oxygen b. provide food for carnivores c. break down dead organisms d. convert sunlight to food energy 22. How do consumers interact with producers? a. Consumers mate with producers. b. Producers decompose consumers. c. Consumers use producers for food. d. Producers use consumers for energy. 23. What type of organisms is always at the base of an ecological pyramid? a. Producers c. Secondary consumers b. Primary consumers d. Tertiary consumers 24. Where does photosynthesis take place in the plant? (Leaves or roots) 25. Organelles called chloroplasts contain chlorophyll and are responsible for the plant being green.
26. What is the process called that converts energy into a sugar and a by-product of oxygen? photosynthesis 27. During photosynthesis, the stoma open to allow carbon dioxide and water into the leaf. Oxygen and water are released through the stoma as well. 28. During photosynthesis, a leaf converts radiant energy into chemical energy. 29. What are the raw materials that go into the process of photosynthesis? Carbon dioxide and water plus adding radiant energy 30. What are the products of photosynthesis? Glucose and oxygen