Lesson Plan

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Lesson Plan
Grade: Date: 17/01/2026
Subject: Biology
Lesson Topic: explain the importance of random sampling in determining the biodiversity of an area
Learning Objective/s:
  • Describe the concept of biodiversity and why it is measured.
  • Explain the principles of random sampling and how it reduces bias.
  • Calculate species‑richness, Shannon‑Wiener, and Simpson’s diversity indices from sample data.
  • Evaluate the consequences of non‑random sampling on biodiversity estimates.
  • Design a simple random quadrat or transect survey for a local habitat.
Materials Needed:
  • Projector and screen
  • Printed handout of the quadrat data table
  • Whiteboard and markers
  • Random number generator (online tool or dice)
  • Calculators or spreadsheet software
  • Sample quadrat frames or tape (optional for outdoor demo)
 Introduction:

Begin with a quick question: “How could we know if a forest is losing species without counting every organism?” Connect this to students’ prior knowledge of species counts and emphasize that reliable data depend on good sampling. State that by the end of the lesson they will be able to explain why random sampling is essential and calculate basic biodiversity indices.
Lesson Structure:
  1. Do‑now (5’): Students list three methods they know for measuring biodiversity and share why each might be limited.
  2. Mini‑lecture (10’): Present the three key principles of random sampling (equal probability, independence, representativeness) with a flowchart diagram.
  3. Guided practice (15’): Using the provided quadrat data, work through calculations of proportions, Shannon‑Wiener index, and Simpson’s index step‑by‑step.
  4. Group activity (15’): In small groups, design a random sampling plan (choose quadrat, transect, or pitfall method), generate random locations, and outline how they would record data.
  5. Check for understanding (5’): Exit ticket – one sentence explaining why random sampling improves biodiversity estimates.
Conclusion:

Recap the link between unbiased sampling and accurate diversity indices, highlighting the key take‑aways. Collect exit tickets and briefly discuss common misconceptions. For homework, assign students to locate a nearby green space, propose a random sampling scheme, and predict which biodiversity index they would calculate.