| Lesson Plan |
| Grade: |
Date: 25/02/2026 |
| Subject: Biology |
| Lesson Topic: explain that transpiration involves the evaporation of water from the internal surfaces of leaves followed by diffusion of water vapour to the atmosphere |
Learning Objective/s:
- Describe the two stages of transpiration (evaporation and diffusion) in leaves.
- Explain how water‑potential gradients drive water movement during transpiration.
- Identify key environmental factors that influence the rate of transpiration.
- Interpret a leaf cross‑section diagram to locate sites of evaporation and diffusion.
- Apply knowledge of transpiration to predict how changes in temperature, humidity, or wind affect water loss.
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Materials Needed:
- Projector or interactive whiteboard
- PowerPoint slides with leaf diagram
- Handout worksheet containing the diagram and questions
- Simple hygrometer or temperature sensor (optional demo)
- Whiteboard and markers
- Sticky notes for exit ticket
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Introduction:
Begin with a quick question: “How do plants stay cool and obtain nutrients?” Connect this to prior knowledge of photosynthesis and water uptake. State that today students will discover how water leaves the plant and why this matters, and they will be able to explain the process by the end of the lesson.
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Lesson Structure:
- Do‑now (5'): Students list everything they know about water loss in plants; brief sharing.
- Mini‑lecture (10'): Explain evaporation and diffusion stages, show cross‑section diagram on screen.
- Guided diagram labeling (12'): Students label printed leaf diagrams and discuss the water‑potential equation.
- Factors investigation (10'): Small groups analyse the factors table, predict how each factor changes transpiration rate, and present findings.
- Check for understanding (5'): Quick quiz (Kahoot/hand‑raise) on key concepts.
- Exit ticket (3'): Write one sentence summarising why transpiration is essential for plants.
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Conclusion:
Recap the two‑step process of transpiration and the main factors that modify its rate. Collect exit tickets to gauge individual understanding, and remind students to complete the worksheet for homework, which asks them to apply the concepts to a real‑world scenario (e.g., desert vs. rainforest plants).
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