Year 7 Science · Unit 1 · Lesson 18
Challenge Worksheet
Learning Goals
Find the mistake
A student wrote this answer
"The cane toad problem in Australia was caused by climate change, which allowed them to spread north. Cane toads are harmful mainly because they compete with native frogs for food. The best solution is to create more national parks, which would protect native species from the toads."
1. Identify at least two mistakes in the student's answer. List them clearly.
2. Write a corrected version of the flawed sentences. Make sure every scientific claim is accurate.
3. Explain why these kinds of mistakes about invasive species are easy to make — what do people commonly misunderstand?
1. Rank the five threats to biodiversity (habitat loss, climate change, invasive species, overexploitation, pollution) from most to least severe for Australian species specifically. Justify each position in your ranking with at least one piece of evidence from the lesson.
2. Australia has cleared approximately 50% of its native vegetation since European settlement, and it holds the world record for mammal extinctions. A politician argues: "We should focus all conservation spending on stopping invasive species, since feral cats alone kill 1.7 billion native animals a year — far more than land clearing does." Do you agree or disagree? Use evidence from the lesson to support your position.
Wrap Up
In one sentence, what was the main idea of this lesson?