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Roles of Organisms in Ecosystems Essential Questions • What are the energy roles of organisms in an ecosystem? Energy Roles • An organism’s energy role is determined by how it obtains or gets energy and interacts with other organisms within an ecosystem. • Each organisms in an ecosystem fills the energy role of producer consumer, or decomposer – this is it’s niche. Producers and their Niche • An organism that can make its own food is a producer. • Energy enters most ecosystems as sunlight, which plants, algae and some bacteria use to make their own food (photosynthesis). • Producers are the source of all food in an ecosystem. • Think about it – have you ever had to give a plant half of your lunch because it was starving? Consumers and their Niche • Consumers cannot make their own food and therefore get food by feeding off of other organisms. • Compare and Contrast: How are producers and consumers similar and different? • Consumers are classified by what they eat. They can be herbivores, carnivores or omnivores. Herbivores • Herbivores are consumers that get their energy from eating only plants. • Can you think of some herbivores? Omnivores • Omnivores are consumers that get energy from eating both plants and animals. • Bears, humans and ____________ are omnivores. Carnivores • Carnivores are consumers that eat only animals. • Lions and spiders are some examples of carnivores. Decomposers and their Niche • Decomposers break down wastes and dead organisms and return nutrients to the ecosystem. • Earthworms, mushrooms and bacteria are decomposers. • Is the niche of a decomposer important? Paparazzi!! • Looking for producers, consumers and decomposers in our ecosystem! • Grab your science notebooks, your pencils and I’ll grab my camera as we go on a hunt for organisms in our ecosystem. Energy Flow in Ecosystems Energy Flows Through Ecosystems • The Sun’s energy can flow through an ecosystem. • As the Sun’s energy enters most ecosystems it is converted into food by producers. • This energy is transferred to each organism that eats a producer and then to other organisms that feed on these consumers. Food Chain and Webs • The movement of energy through an ecosystem can be shown in diagrams called food chains and food webs. • A food chain is a series of events in which one organism (predator) eats another (prey) and obtains energy. • It shows one possible path that energy can flow. Levels in a Food Chain • All food chains have different levels of consumers. Producer First level consumer Second consumer A Food Web • Do you eat the same thing every day? • A Food Web is a combination of many food chains. • Consumers and producers belong to many different food chains. Red arrows show energy moving from second-level consumers to third-level consumers. Yellow arrows show energy moving from first-level consumers to second-level consumers. Blue arrows show the movement of energy from producers to first-level consumers. Producers form the base of the food web. Decomposers consume the wastes and remains of other organisms. Bacteria Energy Pyramid • A diagram called an energy pyramid shows the amount of energy that moves from one feeding level to another in a food web. • 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. • Why do you think this happens? Third-Level Consumers (1 kcal) Second-Level Consumers (10 kcal) First-Level Consumers (100 kcal) Producers (1,000 kcal) Energy Pyramids • When an organism in an ecosystem eats, it obtains energy. The organism uses some of this energy to move, grow, reproduce, and carry out other life activities. • This means that only some of the energy it obtains will be available to the next organism in the food web. What Eats What? • In your groups research a food chain that exist within each type of ecosystem below: • • • • Ocean Forest Desert Wetland • Use a flow chart to show your work. • There are books and computers for you to use!