Lesson Plan

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Lesson Plan
Grade: Date: 25/02/2026
Subject: Biology
Lesson Topic: explain that natural selection occurs because populations have the capacity to produce many offspring that compete for resources; in the ‘struggle for existence’, individuals that are best adapted are most likely to survive to reproduce and pass on t
Learning Objective/s:
  • Describe the five key components of natural selection (variation, over‑production, struggle for existence, survival of the fittest, reproductive success).
  • Explain how natural selection changes allele frequencies over successive generations.
  • Compare natural and artificial selection, focusing on agents, time‑scales and typical outcomes.
  • Apply the natural‑selection process to a real‑world example and interpret a simple allele‑frequency calculation.
Materials Needed:
  • Projector and screen
  • PowerPoint slides with key concepts and flowchart
  • Printed handouts (flowchart cards, worksheet, allele‑frequency problem)
  • Whiteboard and markers
  • Short video clip on peppered moths
  • Clicker/quiz app for exit ticket
 Introduction:
Begin with a 2‑minute video of peppered moth colour change to hook interest. Prompt students to recall how variation arises in populations and ask what might drive a shift in colour. State the success criteria: by the end of the lesson students will be able to list the steps of natural selection, explain its effect on allele frequencies, and contrast it with artificial selection.
Lesson Structure:
  1. Do‑now (5’) – quick paper quiz on variation and over‑production.
  2. Mini‑lecture with slides (10’) – introduce key concepts and the six steps of natural selection.
  3. Flowchart activity (12’) – in groups, students arrange printed cards to illustrate the natural‑selection process.
  4. Case‑study analysis (8’) – examine the peppered moth example and discuss changes in allele frequency.
  5. Comparison discussion (8’) – use the provided table to contrast natural vs. artificial selection.
  6. Guided practice (5’) – calculate a simple allele‑frequency change using the formula p' = (p·wA)/ w̄.
  7. Exit ticket (2’) – students write one sentence summarising why natural selection occurs.
Conclusion:
Recap the five components and the flow of natural selection, highlighting the link to allele‑frequency change. Ask students to share one key takeaway on a sticky note and collect them as a formative check. For homework, assign the textbook section on natural vs. artificial selection with three short questions to reinforce understanding.