Lesson Plan

Resources → Subject Notes → Biology → Notes
Lesson Plan
Grade: Date: 25/02/2026
Subject: Biology
Lesson Topic: explain the role of the dominant allele, Le, that codes for a functional enzyme in the gibberellin synthesis pathway, and the recessive allele, le, that codes for a non-functional enzyme
Learning Objective/s:
  • Describe how the dominant allele Le produces a functional enzyme in the gibberellin synthesis pathway.
  • Explain the effect of the recessive allele le on enzyme activity and gibberellin levels.
  • Analyse the relationship between genotype, gibberellin concentration, and plant phenotype.
  • Apply knowledge of Le/le to predict phenotypic outcomes in breeding scenarios.
Materials Needed:
  • Projector or interactive whiteboard
  • PowerPoint slides with pathway diagram
  • Handout summarising genotype‑phenotype table
  • Sample seed packets (tall vs dwarf varieties) for discussion
  • Worksheets for genotype‑phenotype analysis
  • Markers and chart paper for group activity
 Introduction:
Begin with a quick image of a towering wheat plant beside a dwarf variety to spark curiosity. Review prior learning on genes, alleles, and plant hormones, confirming that students understand the basics of dominant and recessive traits. State that by the end of the lesson they will be able to explain how the Le and le alleles control gibberellin synthesis and predict resulting plant phenotypes.
Lesson Structure:
  1. Do‑now (5') – students label a simple genotype‑phenotype diagram on a worksheet.
  2. Mini‑lecture (10') – present the Le/le pathway, enzyme function, and gibberellin role using slides.
  3. Guided analysis (10') – work through the table of genotypes, enzyme activity, GA levels, and phenotypes, asking probing questions.
  4. Group activity (15') – teams use seed packet examples to predict height outcomes and design a breeding plan, recording on chart paper.
  5. Check for understanding (5') – quick quiz (Kahoot/handout) with scenario questions.
  6. Summary discussion (5') – teacher reinforces key concepts and links to real‑world breeding.
Conclusion:
Summarise that the dominant Le allele enables normal gibberellin production and typical growth, while the recessive le allele blocks the pathway leading to dwarfism. Ask each student to write one exit‑ticket sentence predicting the phenotype of a given genotype under stress. Assign homework to read a case study on dwarf wheat breeding and prepare a short reflection.