Year 8 Science · Unit 1 · Lesson 20
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Learning Goals
Odd one out
Circle the item that does not belong in each group. Then explain why it doesn't fit. The odd one out should be non-obvious, look for the deeper connection between the other three.
| # | Group | Your answer (odd one + reason) |
|---|---|---|
| 1 | Xylem Phloem Red blood cell Vein | |
| 2 | Stomata Alveoli Gills Xylem | |
| 3 | Shivering Sweating Vasodilation Digestion | |
| 4 | Liver Kidney Skin Heart | |
| 5 | Food web Feedback loop Predator-prey Habitat |
Synthesis scenario, Australia's platypus
The platypus (Ornithorhynchus anatinus) hunts underwater in cold Australian creeks where water temperatures can drop to 15°C. Despite this, a platypus must maintain its core body temperature at approximately 32°C to keep enzyme-controlled processes running efficiently. It uses a combination of metabolic heat, specialised blood circulation, and dense fur to achieve this.
Describe how a platypus maintains its body temperature at 32°C in 15°C creek water. In your answer, name every organ system involved and explain the role each system plays. Use the chain: structure → role → function → effect on body temperature.
1. A platypus has webbed feet suited for swimming and a bill for detecting electrical signals from prey. Name the concept that links body structure to function and explain how it applies here.
2. If a platypus's circulatory system was disrupted so it could no longer redirect blood flow away from its extremities, predict what would happen to its core body temperature and explain why.
Wrap Up
In one sentence, explain why living systems need multiple organ systems working together, not just one.