Lesson Plan

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Lesson Plan
Grade: Date: 25/02/2026
Subject: Biology
Lesson Topic: Describe translocation as the movement of sucrose and amino acids in the phloem from regions of production to regions of use.
Learning Objective/s:
  • Describe the pressure‑flow mechanism that drives phloem translocation.
  • Explain how sucrose and amino acids are loaded at source tissues and unloaded at sink tissues.
  • Identify the main factors that influence the rate of translocation.
  • Compare typical source and sink organs in plants.
  • Predict how environmental changes such as temperature affect phloem transport.
Materials Needed:
  • Projector and screen
  • Printed diagram of the pressure‑flow mechanism
  • Worksheet with source‑sink tables and calculation tasks
  • Interactive phloem‑flow simulation (computer or tablet)
  • Markers and whiteboard
  • Sample plant material (leaf and young root)
 Introduction:
Begin with a quick question: “How do sugars travel from a leaf to a growing fruit?” Connect this to prior learning about xylem transport. State that today students will uncover the mechanism behind sugar movement in the phloem and the criteria for success – being able to diagram the pressure‑flow process and explain source‑sink dynamics.
Lesson Structure:
  1. Do‑now (5') – short quiz on xylem transport to activate prior knowledge.
  2. Mini‑lecture (10') – introduce phloem, source & sink concepts, and the pressure‑flow hypothesis using the projected diagram.
  3. Guided labeling activity (12') – students label parts of a hand‑out diagram (sieve‑tube, companion cell, source, sink).
  4. Group calculation task (15') – using π = iCRT, calculate osmotic pressure for a sample sucrose concentration and discuss how it creates turgor differences.
  5. Think‑pair‑share (8') – discuss how temperature and water availability modify translocation rates.
  6. Formative check (5') – exit ticket: one concise sentence describing the whole translocation process.
Conclusion:
Recap the key steps of the pressure‑flow mechanism and highlight the role of source‑sink relationships. Collect exit tickets to gauge understanding, and assign a homework task to create a real‑world example (e.g., fruit development) illustrating translocation.