Lesson Plan

• Describe how water’s polarity and hydrogen‑bonding make it an effective solvent in biological systems.
• Explain the specific functions of water as a solvent during digestion, excretion and transport.
• Analyse how osmotic gradients facilitate the movement of water to support these processes.
• Apply knowledge of water’s solvent role to predict the impact of dehydration on nutrient absorption and waste removal.

• Projector or interactive whiteboard
• PowerPoint slides with diagrams of digestion, excretion and transport
• Handout summarising key points and a short worksheet
• Model of a human digestive system (optional)
• Water‑solvent demonstration kit (e.g., sugar in water)
• Exit‑ticket cards

Begin with a quick demonstration of sugar dissolving in water to highlight solvent properties. Ask students to recall where they have seen water act as a medium in the body. Outline today’s success criteria: students will be able to describe water’s role in digestion, excretion and transport and link these to osmosis.

1. Do‑Now (5'): Students write three examples of water acting as a solvent in everyday life.
2. Mini‑lecture (10'): Explain polarity, hydrogen bonding and why water dissolves polar substances.
3. Guided exploration (12'): Use the slide deck to examine water’s role in digestion, excretion and transport; pause for Q&A after each system.
4. Interactive activity (10'): In pairs, students complete a worksheet matching organ functions with the solvent role of water.
5. Concept check (8'): Quick Kahoot quiz on osmosis and solvent functions.
6. Summative discussion (5'): Students summarise how osmotic movement underpins the three processes.

Recap the key points: water’s polarity, its solvent role in digestion, excretion and transport, and the driving force of osmosis. Students complete an exit ticket stating one way dehydration would affect each of the three processes. Assign a short homework: create a labelled diagram showing where water acts as a solvent in the human body.