Lesson Plan

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Lesson Plan
Grade: Date: 17/01/2026
Subject: Biology
Lesson Topic: explain the meanings of the terms haploid (n) and diploid (2n)
Learning Objective/s:
  • Describe the definitions of haploid (n) and diploid (2n) cells.
  • Explain how meiosis produces haploid gametes.
  • Illustrate how fertilisation restores diploidy and transmits genetic information.
  • Compare normal ploidy with abnormal conditions such as triploidy and trisomy 21.
Materials Needed:
  • Projector and screen
  • Whiteboard and markers
  • Printed diagram of meiosis and fertilisation
  • Worksheet with chromosome tables
  • Student response cards
 Introduction:
Begin with a quick poll: “How many chromosomes are in a typical human cell?”
Students recall that somatic cells contain 46 chromosomes (2n).
Success criteria: by the end of the lesson they will correctly label haploid and diploid cells and explain their role in inheritance.
Lesson Structure:
  1. Do‑now (5') – poll results recorded on response cards.
  2. Mini‑lecture (10') – definitions of haploid (n) and diploid (2n) with human examples.
  3. Interactive diagram (10') – projected schematic; students label cell types and chromosome numbers.
  4. Guided worksheet activity (15') – work through meiosis stages and identify resulting ploidy.
  5. Think‑pair‑share (5') – discuss consequences of abnormal ploidy (triploidy, trisomy 21).
  6. Quick check (5') – exit ticket: write one concise definition of haploid and one of diploid.
Conclusion:
Recap the key points: haploid cells carry one chromosome set, diploid cells carry two, and fertilisation restores the diploid number.
Students submit their exit tickets, providing immediate feedback on understanding.
Homework: complete an online quiz covering meiosis, haploid/diploid concepts, and abnormal ploidy.