Is Our Planet Healthy?

Teacher Tips

Hook

• It helps to expect the white beach to win the vote, because that’s exactly what you want. Bare white sand supports very little life compared with the muddy woodland floor that comes last. Let the class commit before you say anything, as the vote is the evidence you’ll come back to.
• The muddy floor is the one to return to. You might ask “What is actually happening in the mud?” and keep asking until someone says something is being broken down. Learners often describe it as dead, but it’s the one image where you can see the work of an ecosystem taking place.

ITZA Pathways

• Listen out for the word “disgusting”. It’s an honest reaction, and it holds the whole misconception in one word. This question helps challenge it: “If nothing rotted, where would the nutrients go?” Nowhere, and nothing new could grow.
• Bioaccumulation in Pathway 2 is the hardest idea in the session, so it’s the one most likely to be skimmed. Learners often assume a small amount of pollution is diluted away. Try asking “What happens to the poison inside a fish when a bigger fish eats it?” It’s worth catching here, because it comes back in the scenarios.

Classroom Activity

• It helps to work the vulture example all the way through with the whole class, answering all four questions out loud. Question two, “What happens next?”, is the one groups tend to skip, and it’s the only question in the set that asks them to think rather than report.
• The extra details reveal is the best mechanic in the session, so it’s worth protecting. Hold it until every group has committed to an answer, then let them revise. A group that changes its mind with new evidence has done real science; a group that receives the details first has done comprehension.
• Question four tends to produce “stop polluting” and “plant more trees” unless you ask for more. You might push for something specific to their scenario, and for who would actually have to do it. Vague answers here are a sign the group hasn’t yet understood their own ecosystem.

Plenary

• Expect vultures and bees, because those are the vivid ones. The answer worth steering towards is less about any one animal and more that the unglamorous parts of nature turned out to be doing the work.
• The lock-in is from Dr Jane Goodall, the primatologist and conservationist famous for her decades of work with wild chimpanzees in Tanzania. She says every creature plays a part in its ecosystem, whether that’s building soil, pollinating plants or keeping other populations in balance, which is exactly what the class has just seen. You might close by asking “Which creature today was doing a job you hadn’t noticed?”
• Somebody is likely to test that idea with mosquitoes, wasps or parasites. That’s a good challenge, not a derailment. The honest answer is that an ecosystem doesn’t need every single species, but it does need many of them, and ‘purpose’ is shorthand for a role in a system rather than a job someone assigned.