--- marp: true theme: default html: true --- # Who eats whom? Year 7 Biology · Food webs and ecosystems --- ## Today **We are learning to** a food web joins all the food chains in an ecosystem. Arrows point the way energy flows, from the food to the eater. Every organism is a producer, a consumer or a decomposer, and decomposers include microorganisms. - I can construct a food web from a list of organisms. - I can draw arrows in the direction of energy flow. - I can identify producers, consumers and decomposers, including microorganisms. --- ## Why it matters > A kookaburra eats lizards, grasshoppers, even small snakes. A food chain can only show one of those meals. How do you show all of them? --- 💬 Discussion ## Engage: predict **In a food web, grass is eaten by a grasshopper. Which way should the arrow point?** - Either way, as long as it's labelled - From the grass to the grasshopper (energy goes into the grasshopper) - From the grasshopper to the grass (the grasshopper eats it) --- ✍️ Activity ## Explore it {{embed: https://studio.learningwaypoints.com/tutorials/_playground-board/index.html?id=deck%2Fscience%2Fbiology-7%2Ffood-webs%2Fstep-2&code=widget%3A+foodweb%0Aorganism+G%3A+Grass%0Aorganism+H%3A+Grasshopper%0Aorganism+R%3A+Kangaroo%0Aorganism+L%3A+Lizard%0Aorganism+B%3A+Kookaburra%0Aorganism+D%3A+Dingo%0Aorganism+F%3A+Fungi+and+bacteria%2C+decomposer%0Aeats+H%3A+G%0Aeats+R%3A+G%0Aeats+L%3A+H%0Aeats+B%3A+L%2C+H%0Aeats+D%3A+R%0Aeats+F%3A+G%2C+D%0A&fresh=1}} [Open this step in the tutorial](https://studio.learningwaypoints.com/tutorials/science/biology-7/food-webs/?full=step-2#step-2) --- ✅ Check ## What happened? * From the grass to the grasshopper. Arrows show the way energy flows: from the food into the eater. --- ✅ Check ## Roles **What is each organism's role in the bush web?** Groups: Producer · Primary consumer · Secondary consumer · Decomposer Grass · Grasshopper · Kangaroo · Lizard · Dingo · Fungi and bacteria * Answer: Grass → Producer; Grasshopper → Primary consumer; Kangaroo → Primary consumer; Lizard → Secondary consumer; Dingo → Secondary consumer; Fungi and bacteria → Decomposer --- ✅ Check ## More than one level **The kookaburra eats both lizards and grasshoppers. What does that make it?** - A secondary consumer when it eats grasshoppers, and a tertiary consumer when it eats lizards - A producer - A primary consumer * Answer: A secondary consumer when it eats grasshoppers, and a tertiary consumer when it eats lizards --- ✅ Check ## Decomposers **Why do decomposers belong in a food web?** - They don't; only animals that hunt belong - They make food from sunlight - They feed on dead organisms and wastes from every level, returning nutrients to the soil * Answer: They feed on dead organisms and wastes from every level, returning nutrients to the soil --- ✅ Check ## Mix it up **Looking back at the kingdoms: a mushroom grows on a dead log. How does it get its food?** - It absorbs food from the dead log: it is a fungus, so it is a decomposer - It hunts and eats small animals - It makes food from the soil, like a plant - It makes food from sunlight, like a plant * Answer: It absorbs food from the dead log: it is a fungus, so it is a decomposer --- ✅ Check ## Elaborate: chain or web? **The food chain grass → grasshopper → lizard → kookaburra is part of the web. What does the chain leave out?** - The direction of energy flow - Other foods each animal eats, and other animals that eat the same food - Nothing: a chain and a web show the same thing * Answer: Other foods each animal eats, and other animals that eat the same food --- ✍️ Activity ## Elaborate: an Antarctic web {{embed: https://studio.learningwaypoints.com/tutorials/_playground-board/index.html?id=deck%2Fscience%2Fbiology-7%2Ffood-webs%2Fstep-6&code=widget%3A+foodweb%0Aorganism+P%3A+Phytoplankton%0Aorganism+K%3A+Krill%0Aorganism+F%3A+Small+fish%0Aorganism+S%3A+Squid%0Aorganism+E%3A+Penguin%0Aorganism+L%3A+Leopard+seal%0Aorganism+B%3A+Bacteria%2C+decomposer%0Aeats+K%3A+P%0Aeats+F%3A+K%0Aeats+S%3A+F%2C+K%0Aeats+E%3A+F%2C+K%2C+S%0Aeats+L%3A+E%2C+F%0Aeats+B%3A+P%2C+L%0A&fresh=1}} [Open this step in the tutorial](https://studio.learningwaypoints.com/tutorials/science/biology-7/food-webs/?full=step-6#step-6) --- ## Evaluate: look back Write one sentence: "At first I thought… Now I think… because…" **Revision summary** - A **food web** joins all the food chains in an ecosystem. - **Arrows point the way energy flows**: from the food to the eater. - **Producers** make their own food; **consumers** eat other organisms (primary, secondary…); **decomposers** (fungi and bacteria, microorganisms) break down dead matter and wastes. - One animal can feed at more than one level. --- ✅ Check ## Exit ticket **In a food web, why does the arrow point from the gum leaves to the koala?** * Arrows show the direction energy flows: from the food (gum leaves) into the eater (koala).