| Lesson Plan |
| Grade: |
Date: 25/02/2026 |
| Subject: Biology |
| Lesson Topic: Describe the intake of carbon dioxide and water by plants relating to leaf structure and the distribution of chloroplasts. |
Learning Objective/s:
- Describe how carbon dioxide enters the leaf and how water is transported to the mesophyll.
- Explain the role of cuticle, epidermis, stomata, mesophyll and veins in gas and water exchange.
- Analyse the distribution of chloroplasts in palisade and spongy mesophyll and its effect on photosynthetic efficiency.
- Apply this knowledge to predict the impact of stomatal closure on CO₂ uptake and transpiration.
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Materials Needed:
- Projector and screen
- PowerPoint slides with a labelled leaf diagram
- Printed handouts of a leaf cross‑section for each student
- Whiteboard and markers
- Interactive quiz platform (e.g., Kahoot)
- Fresh leaf samples (optional) for observation
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Introduction:
Imagine a leaf as a tiny factory that breathes in carbon dioxide and drinks water. Students already know the basic photosynthesis equation, so we will connect that knowledge to leaf anatomy. By the end of the lesson you will be able to label key leaf structures and explain how they enable CO₂ and H₂O intake.
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Lesson Structure:
- Do‑now (5') – quick Kahoot quiz recalling the photosynthesis equation and the need for CO₂ and H₂O.
- Mini‑lecture (10') – present a labelled cross‑section of a leaf, highlighting cuticle, epidermis, stomata, palisade & spongy mesophyll, and veins.
- Guided activity (12') – students label their printed leaf handouts and discuss the function of each structure in pairs.
- Process‑flow task (10') – groups create flowcharts showing the pathways of CO₂ diffusion and water movement from roots to chloroplasts.
- Check for understanding (8') – teacher asks targeted questions; students complete an exit‑ticket sentence: “If the stomata close, …”.
- Consolidation (5') – whole‑class summary linking chloroplast distribution to light capture and gas exchange efficiency.
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Conclusion:
We reviewed how leaf structure coordinates the uptake of CO₂ and water and why chloroplasts are concentrated in the palisade layer. Students hand in their exit‑ticket sentences as a formative check. For homework, they will write a short paragraph predicting how drought‑induced stomatal closure affects photosynthetic rate.
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