https://www.khanacademy.org/science/ap-biology/ecology-ap/energy-flow-through-ecosystems/a/food-chains-food-webs 2026-07-02T07:00:35.721045782Z Learn: Food chains & food webs How food chains and food webs represent the flow of energy and matter. Trophic levels and efficiency of energy transfer. article https://www.khanacademy.org/science/als-k-to-12-science/x46c2fc9f8e023990:2nd-quarter/x46c2fc9f8e023990:illustrating-feeding-relationships-food-chains-and-food-webs/e/food-chains-and-food-webs 2021-04-29T07:51:49Z Food chains and food webs Test your knowledge of food chains and food webs! Ashley exercise