The lesson plan will enable students to explore trophic levels of organisms by creating a food web that originates with autotrophs, or p lants. Describe environmental changes which cause organisms to thrive, become ill, or perish. Materials Yarn, metal shower curtain rings, notecards with the name of an organism and its food source written on each one, and a chart or poster showing the trophic levels of organisms. A food web links organisms with their food sources, as well as the organisms for which they are a food source. The circles radiating out from the center of a web correlate with the trophic levels.
Plants are primary producers at the center of the web.
They are autotrophs, which means that they make their own food. The next circle of the web consists of the primary consumers, or herbivores, which eat plants. The next layer of the web is the se condary consumers, or carnivores, which eat the primary consumers. Both primary and secondary consumers are called heterotrophs. This is because they do not make their own food, but must rely on another source for food.