Lesson Plan

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Lesson Plan
Grade: Date: 25/02/2026
Subject: Biology
Lesson Topic: describe the principle of the universal genetic code in which different triplets of DNA bases either code for specific amino acids or correspond to start and stop codons
Learning Objective/s:
  • Describe the universal genetic code and its role in translating DNA sequences into proteins.
  • Explain how codons specify amino acids, start signals, and stop signals.
  • Analyze the degeneracy of the code and predict the outcome of given DNA triplets.
  • Apply knowledge of start and stop codons to interpret a simple DNA codon table.
Materials Needed:
  • Projector or interactive whiteboard
  • PowerPoint slides with codon table
  • Handout of DNA codon chart
  • Colored markers or sticky notes for group activity
  • Worksheets with codon translation exercises
 Introduction:
Begin with a quick video clip showing how a cell builds a protein from DNA instructions, capturing students' curiosity. Review prior learning about DNA structure and transcription to connect to today's focus. Explain that by the end of the lesson they will be able to describe the universal genetic code and identify start and stop codons.
Lesson Structure:
  1. Do‑now (5’) – Students match DNA triplets to amino acids on a mini‑poster to activate prior knowledge.
  2. Mini‑lecture (10’) – Present the universal genetic code, emphasizing the 64 codons, degeneracy, start (ATG/AUG) and stop codons, using slides and the codon table.
  3. Guided practice (12’) – In pairs, learners use a printed codon chart to translate a short DNA sequence, marking start and stop sites.
  4. Interactive simulation (10’) – Demonstrate transcription and translation on the interactive whiteboard, showing ribosome movement and release factors.
  5. Check for understanding (8’) – Quick quiz via Kahoot/exit poll with questions on codon identification.
  6. Consolidation (5’) – Whole‑class discussion summarising key principles and correcting misconceptions.
Conclusion:
Recap the main ideas: each codon is a three‑base signal that directs amino‑acid incorporation, with specific start and stop signals. Students complete an exit ticket by writing one example of a start codon and one stop codon. For homework, assign a worksheet where they translate a longer DNA segment using the codon table.