Biology Year 11 - Module 4 - Lesson 14
Keystone Species, Introduced Species and Ecological Disruption
1. Key Ideas
A single sea otter eats about 9 kg of sea urchins per day. Without otters, urchin populations explode, overgrazing kelp forests into barrens that support almost nothing. The otter is a keystone species — its impact is wildly out of proportion to its numbers. Australia has its own keystone predators, and it also carries some of the world’s most devastating introduced species. This lesson connects both stories.
- Key facts and terms for Keystone Species, Introduced Species and Ecological Disruption
- How the main ideas in Keystone Species, Introduced Species and Ecological Disruption connect
2. Success Criteria
By the end, you should be able to:
- Key facts and terms for Keystone Species, Introduced Species and Ecological Disruption
- Where this lesson fits in Module 4
- How the main ideas in Keystone Species, Introduced Species and Ecological Disruption connect
3. Key Terms
4. Activity: Build the Lesson Map
Use the lesson to complete the table. Keep answers brief but specific.
| Prompt | Your answer |
|---|---|
| Main concept | |
| Important example | |
| Common mistake to avoid | |
| How this links to the next lesson |
5. Short Answer Questions
1. Q1. If dingoes were eradicated from the Simpson Desert, predict what would happen to the spinifex grassland and the animals that live in it within five years. Consider herbivores, vegetation, and soil in your prediction.
2. Q2. The cane toad was introduced to Australia to control beetle pests in sugar cane. It failed to control the beetles but thrived in the wild. Predict why an introduced species might thrive even when it fails at its intended purpose.
3. Q1. If dingoes were eradicated from the Simpson Desert, predict what would happen to the spinifex grassland and the animals that live in it within five years. Consider herbivores, vegetation, and soil in your prediction.
6. Extend: Apply the Idea
A student gives a memorised answer about Keystone Species, Introduced Species and Ecological Disruption but does not use evidence or reasoning.
Improve the answer by writing a stronger response that uses accurate terminology, a relevant example and a clear explanation.
7. Multiple Choice
1. What is the best first step when answering a question about Keystone Species, Introduced Species and Ecological Disruption?
A. Identify the key concept being tested
B. Write every fact from memory
C. Ignore the command word
D. Skip examples and evidence
2. Which answer would show stronger understanding of Keystone Species, Introduced Species and Ecological Disruption?
A. An answer with accurate terms and reasoning
B. A copied definition only
C. A single-word response
D. An answer with no example
3. What should you do if a question asks you to explain?
A. Link the idea to a reason or cause
B. List unrelated facts
C. Only draw a diagram
D. Write the shortest possible answer
8. Success Criteria Proof
Finish with evidence that you can do each success criterion.