Lesson Plan

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Lesson Plan
Grade: Date: 17/01/2026
Subject: Biology
Lesson Topic: explain the genetic basis of discontinuous variation and continuous variation
Learning Objective/s:
  • Describe the genetic mechanisms underlying discontinuous (Mendelian) variation.
  • Explain polygenic inheritance and environmental influence in continuous variation.
  • Compare inheritance patterns and phenotypic distributions of discontinuous and continuous traits.
  • Apply Punnett squares and heritability concepts to predict trait outcomes.
Materials Needed:
  • Projector and screen for slides/diagrams
  • Whiteboard and markers
  • Handouts with trait tables and Punnett‑square exercises
  • Worksheets for calculating heritability
  • Sample phenotype cards (e.g., flower colour, blood type)
  • Laptop with internet access for an interactive quiz
 Introduction:
Begin with a quick poll: “Do you think eye colour is controlled by one gene or many?” This activates prior knowledge of Mendelian traits and sets the stage for exploring more complex variation. Explain that today’s success criteria are to identify genetic bases of both discontinuous and continuous traits and to compare their inheritance patterns.
Lesson Structure:
  1. Do‑now (5’) – students answer the poll question on cards and discuss briefly.
  2. Mini‑lecture (10’) – define variation, differentiate discontinuous vs continuous, and display side‑by‑side diagrams.
  3. Interactive activity (15’) – pairs complete Punnett squares for a discontinuous trait (flower colour) using handouts.
  4. Guided inquiry (15’) – analyse a polygenic trait (human height) with a worksheet to calculate genetic vs environmental variance.
  5. Comparison task (10’) – groups fill a Venn diagram comparing the two types; teacher checks misconceptions.
  6. Formative quiz (5’) – Kahoot/clicker questions to confirm understanding before concluding.
Conclusion:
Summarise that discontinuous traits follow simple Mendelian patterns while continuous traits involve many genes and environmental effects, producing a bell‑shaped distribution. Ask students to write one key difference on an exit ticket, and assign homework to research a real‑world example of each variation type and prepare a one‑minute explanation.