Lesson Plan

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Lesson Plan
Grade: Date: 25/02/2026
Subject: Biology
Lesson Topic: use Simpson’s index of diversity (D) to calculate the biodiversity of an area, and state the significance of different values of D (the formula for Simpson’s index of diversity will be provided, as shown in the Mathematical requirements)
Learning Objective/s:
  • Calculate Simpson’s index of diversity (D) for a given dataset using the provided formula.
  • Interpret D values to assess levels of biodiversity and ecosystem health.
  • Explain how species richness and evenness influence the index.
  • Apply the index to real‑world ecological data and communicate findings.
Materials Needed:
  • Projector or interactive whiteboard
  • Printed worksheet with sample species data
  • Calculator or spreadsheet software
  • Whiteboard and markers
  • Handout of Simpson’s index formula and interpretation table
 Introduction:
Begin with a quick poll: How many different plant species can you spot in the school garden? Review the concepts of species richness and evenness before introducing Simpson’s index as a way to combine them. Explain that by the end of the lesson students will be able to calculate D and interpret what the value says about biodiversity.
Lesson Structure:
  1. Do‑now (5') – Students list species observed in a provided garden photo and discuss richness vs. evenness.
  2. Mini‑lecture (10') – Present the Simpson’s index formula, define variables, and show the worked example on screen.
  3. Guided practice (15') – In pairs, students use the worksheet data to compute N, Σni(ni‑1), and D, with teacher circulating for questions.
  4. Interpretation activity (10') – Groups compare their D values to the interpretation table and write a brief ecological significance statement.
  5. Whole‑class debrief (5') – Selected groups share results; teacher highlights common misconceptions and reinforces the link between D and ecosystem health.
  6. Exit ticket (5') – Students answer: “If D = 0.15, what does that tell you about the community?”
Conclusion:
Summarise that Simpson’s index quantifies both species number and evenness, giving a single measure of biodiversity. Remind students to use the formula and interpretation table for any dataset they encounter. For homework, assign a short task to collect species counts from a local park and calculate D.