| Lesson Plan |
| Grade: |
Date: 25/02/2026 |
| Subject: Biology |
| Lesson Topic: explain, with examples, that phenotypic variation is due to genetic factors or environmental factors or a combination of genetic and environmental factors |
Learning Objective/s:
- Describe phenotypic variation and differentiate genetic, environmental, and gene‑environment interaction factors.
- Explain how specific examples (e.g., flower colour, temperature‑dependent sex) illustrate each factor.
- Analyse how multiple factors combine to shape a trait such as human height.
- Apply knowledge to classify novel traits as genetically, environmentally, or interactively determined.
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Materials Needed:
- Projector and screen
- PowerPoint slides summarising key concepts
- Printed handouts with the summary table
- Whiteboard and markers
- Coloured beads/flower models for demonstration
- Worksheets for classification activity
- Kahoot/quiz platform for formative check
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Introduction:
Begin with the question, “If identical twins are raised in different environments, why might they look different?” Connect this to students’ prior knowledge that DNA encodes traits. Explain that today they will identify whether a trait’s variation is genetic, environmental, or a combination, and they will be able to justify their classification.
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Lesson Structure:
- Do‑now (5'): Think‑pair‑share – list traits that vary among classmates.
- Mini‑lecture (10'): Definitions of phenotypic variation, genetic vs. environmental factors, with slide examples.
- Interactive case studies (15'): Small groups analyse three examples (Petunia flower colour, turtle temperature‑dependent sex, human height) and classify the underlying factor.
- Gene‑environment interaction demo (10'): Show short video of Daphnia predator‑induced helmets; discuss the concept.
- Guided practice (10'): Complete a worksheet matching additional traits to factor categories.
- Formative check (5'): Kahoot quiz covering key terminology and examples.
- Summary & reflection (5'): Recap main points; exit ticket – write one new example and indicate whether it is genetic, environmental, or both.
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Conclusion:
Summarise that phenotypic variation can arise from genes, the environment, or their interaction, and that many traits involve a blend of both influences. Collect exit tickets to gauge understanding, and assign a homework task: find a local plant or animal trait, describe the factor(s) influencing its variation, and be prepared to share in the next lesson.
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