Lesson Plan

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Lesson Plan
Grade: Date: 18/01/2026
Subject: Biology
Lesson Topic: explain what is meant by homologous pairs of chromosomes
Learning Objective/s:
  • Describe the definition and key characteristics of homologous chromosome pairs.
  • Explain how homologous pairs facilitate meiosis and generate genetic variation.
  • Identify the number of homologous pairs in human cells and distinguish autosomes from sex chromosomes.
  • Analyse the impact of pairing errors on genetic disorders such as aneuploidy.
  • Apply knowledge to interpret diagrams of homologous chromosomes during synapsis.
Materials Needed:
  • Projector or interactive whiteboard
  • PowerPoint slides with chromosome diagrams
  • Printed worksheet on chromosome pairing
  • Set of chromosome model cards (maternal & paternal)
  • Markers and chart paper for group summaries
  • Exit‑ticket slips
 Introduction:
Begin with a quick poll asking students to recall the difference between diploid and haploid cells. Link this to their prior knowledge of chromosomes and state that today they will uncover why chromosomes appear in matching pairs. Success will be measured by their ability to define homologous pairs and explain their role in meiosis.
Lesson Structure:
  1. Do‑now (5') – short quiz on diploid vs. haploid chromosome numbers.
  2. Mini‑lecture (10') – definition, length, centromere position, banding pattern, and gene loci of homologous pairs using slides.
  3. Guided analysis (10') – examine the human chromosome table; students label autosomes and sex chromosomes.
  4. Model activity (10') – in pairs, students match maternal and paternal chromosome cards to form homologous pairs and record observations.
  5. Video demonstration (5') – synapsis and crossing‑over during meiosis I.
  6. Think‑pair‑share (5') – discuss why accurate pairing is crucial for preventing genetic disorders.
  7. Formative check (5') – Kahoot quiz on key concepts.
Conclusion:
Recap the definition of homologous pairs and their significance for meiosis and genetic health. Students complete an exit ticket describing one way homology influences inheritance. Assign a brief homework: research a real‑world example of a disorder caused by homologous‑pair mis‑segregation and prepare a one‑minute summary.