Biology · Grade 12

Active learning ideas

The Kidney and Nephron Function

Active learning works for nephron function because students must visualize and manipulate three-dimensional structures to grasp how filtration and reabsorption happen in sequence. Blood pressure, pore sizes, and transport proteins become concrete when students build models or move filtrate through stations, turning abstract processes into memorable experiences.

• Ontario Curriculum Expectations
• HS-LS1-2

• 25–50 min
• Pairs → Whole Class
• 4 activities

Activity 01

• Case Study Analysis
• 35 min · Pairs

Pairs: Nephron Model Construction

Provide pipe cleaners, labels, and diagrams for pairs to build a 3D nephron model. Students identify and label glomerulus, Bowman's capsule, tubules, and loop of Henle, then trace filtrate path with string. Pairs present one process, such as reabsorption, to the class.

How does the nephron filter blood while selectively reabsorbing essential nutrients?

Facilitation Tip

During Nephron Model Construction, circulate with a checklist to ensure pairs include the glomerulus, Bowman’s capsule, and tubule regions with correct labels and relative sizes.

What to look for

Provide students with a diagram of a nephron. Ask them to label the glomerulus, Bowman's capsule, proximal convoluted tubule, loop of Henle, distal convoluted tubule, and collecting duct. Then, have them write one sentence describing the primary function occurring in the proximal convoluted tubule.

• Analyze
• Evaluate
• Create
• Decision-Making
• Self-Management

Activity 02

• Case Study Analysis
• 45 min · Small Groups

Small Groups: Filtration Demo

Groups use coffee filters as glomeruli, funnels for Bowman's capsule, saltwater with food coloring for plasma, and beads for proteins. Pour solution to observe filtration, then add glucose strips to test reabsorption simulation. Record what passes and discuss selectivity.

Trace the path of filtrate through the different parts of the nephron.

Facilitation Tip

For the Filtration Demo, prepare two sets of filters (coffee filter and dialysis tubing) so small groups can compare pore sizes and discuss why proteins remain in the blood.

What to look for

Pose the question: 'If a patient's urine sample shows a significant amount of glucose, what part of the nephron's function is likely impaired and why?' Students write their answers on mini-whiteboards or paper to hold up for immediate feedback.

• Analyze
• Evaluate
• Create
• Decision-Making
• Self-Management

Activity 03

• Stations Rotation
• 50 min · Small Groups

Stations Rotation: Nephron Processes

Set up stations: filtration (pressure demo with syringes), reabsorption (dialysis bag in sugar solution), loop of Henle (salt gradient tubes), secretion (pH adjustment). Groups rotate every 10 minutes, noting observations and sketching mechanisms.

Explain the role of the glomerulus and Bowman's capsule in blood filtration.

Facilitation Tip

At the Nephron Processes stations, assign each group a role (recorder, presenter, builder) to keep all students engaged and accountable for the content.

What to look for

Facilitate a class discussion with the prompt: 'Imagine a scenario where the body is severely dehydrated. How would the nephron's reabsorption processes change to conserve water, and what hormone would be involved?'

• Remember
• Understand
• Apply
• Analyze
• Self-Management
• Relationship Skills

Activity 04

• Case Study Analysis
• 25 min · Whole Class

Whole Class: Filtrate Path Relay

Divide class into teams; each student represents a nephron segment and holds a sign. Pass a 'filtrate ball' while calling out what happens at their station. Teams compete to complete path accurately, then debrief errors.

How does the nephron filter blood while selectively reabsorbing essential nutrients?

Facilitation Tip

During the Filtrate Path Relay, time the relay so students practice the sequence quickly but deliberately, reinforcing the order of segments without rushing.

What to look for

Provide students with a diagram of a nephron. Ask them to label the glomerulus, Bowman's capsule, proximal convoluted tubule, loop of Henle, distal convoluted tubule, and collecting duct. Then, have them write one sentence describing the primary function occurring in the proximal convoluted tubule.

• Analyze
• Evaluate
• Create
• Decision-Making
• Self-Management

A few notes on teaching this unit

Start with a whole-class sketch of the kidney’s major regions to build spatial awareness before diving into nephron segments. Focus on energy-dependent transport at the proximal tubule first, as this is where most reabsorption happens, and use analogies like a ‘reclaiming station’ to make active transport relatable. Avoid overwhelming students with too many hormones early; introduce ADH and aldosterone only after they grasp basic reabsorption and secretion.

Students will accurately describe the path of filtrate through the nephron and explain the specialized roles of each segment. They will use evidence from their models and demos to justify why most filtrate is reabsorbed rather than excreted, showing understanding of the kidney’s role in homeostasis.

---

Watch Out for These Misconceptions

• During Nephron Model Construction, watch for students who build a model that suggests the kidney filters everything and discards the filtrate immediately.

  Circulate with a chart showing that 99% of filtrate is reabsorbed, and ask pairs to add arrows or labels to their model showing where transporters reclaim glucose and ions. Use the coffee filter demo to connect pore size to what passes through and what stays behind.

• During Filtration Demo, watch for students who assume the dialysis tubing acts like a simple sieve that catches all large particles.

  Ask groups to compare their filtrate samples from the coffee filter and dialysis tubing, then discuss why proteins stay in the blood even though they are smaller than some wastes. Challenge them to explain the role of blood pressure and selective permeability in the glomerulus.

• During Station Rotation: Nephron Processes, watch for students who treat each nephron segment as a separate organ rather than parts of a continuous system.

  At the proximal tubule station, have students trace the path of a water molecule from the glomerulus to the collecting duct using string or arrows on their table. Peer teaching at each station reinforces that the nephron is a single, cooperative pathway.

---

Methods used in this brief

• Case Study Analysis
• Stations Rotation