Biology Year 11 - Module 4 - Lesson 9
Symbiotic Relationships — Mutualism, Commensalism and Parasitism
1. Key Ideas
Beneath every eucalyptus tree in Australia lies a hidden network: microscopic fungal threads woven through the soil, connected to the tree's roots. These fungi do not harm the tree — they feed it. In return, the tree feeds them. This partnership is not optional; without it, Australia's forests would collapse. It is one of millions of symbiotic relationships that hold ecosystems together.
- Key facts and terms for Symbiotic Relationships — Mutualism, Commensalism and Parasitism
- How the main ideas in Symbiotic Relationships — Mutualism, Commensalism and Parasitism connect
2. Success Criteria
By the end, you should be able to:
- Key facts and terms for Symbiotic Relationships — Mutualism, Commensalism and Parasitism
- Where this lesson fits in Module 4
- How the main ideas in Symbiotic Relationships — Mutualism, Commensalism and Parasitism 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. Every eucalyptus tree in NSW has mycorrhizal fungi living on its roots. The fungi extend far into the soil and absorb water and minerals for the tree. Predict what would happen to a eucalyptus forest if all the mycorrhizal fungi suddenly disappeared. Consider tree growth, forest biodiversity, and recovery after fire.
2. Q2. A tick feeds on a kangaroo's blood, weakening the kangaroo and potentially transmitting disease. At the same time, the tick gains food and shelter. Is this relationship mutualism, commensalism or parasitism? Explain your reasoning.
6. Extend: Apply the Idea
A student gives a memorised answer about Symbiotic Relationships — Mutualism, Commensalism and Parasitism 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 Symbiotic Relationships — Mutualism, Commensalism and Parasitism?
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 Symbiotic Relationships — Mutualism, Commensalism and Parasitism?
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.