Quick check: feedback loops and what goes wrong

Classroom resources

Load these into Waypoints Prepare: choose Load URL and paste the copied address, or download the file and import it. In Prepare, the worksheet's Teacher edition shows the answers; the student copy hides them.

• Slides Download Copy address for Prepare Present from the browser, or export to PowerPoint or PDF.
• Worksheet Download Copy address for Prepare Print the student copy; the Teacher edition has the answers.

Students will be able to

• I can name the parts of a feedback loop in an example.
• I can say the set point for body temperature and blood glucose.
• I can say which part of a loop fails in a disorder and what follows.

Timing

Node 6 7 min · Node 7 7 min

Before class

A Quick check: a few questions on what students should know for AC9S9U01 nodes 6 and 7, which you teach in class. It has no board, no clip and no new teaching, and it is optional, so it never holds up course completion. Set the width with ?width=minimum, typical (default) or wider.

Use it as a self-test after your teaching, a starter, or revision. The Feedback lesson on screen does body temperature; blood glucose and the disorders are for class. Name the parts of the loop in your own words consistently so students can transfer them.

Running the lesson

1. Node 6: draw the loop on the board for temperature, then ask students to draw glucose before the questions.
2. Node 7: ask where the loop could break before showing the options.

The hard part (on purpose)

Naming which part fails, not just that something is wrong. When a student says the body cannot control glucose, ask which step stops.

When students get stuck

Answers to the checks

1. Parts of the loop: Which part of the temperature loop is it?
   Temperature sensors in the skin and blood → Receptor; The hypothalamus in the brain → Control centre; Sweat glands → Effector; Muscles that shiver → Effector; Nerve endings that detect cold → Receptor
2. Blood glucose: Blood glucose rises after a meal. What reverses the change?
   Insulin is released, cells take up glucose, and blood glucose falls back towards its set point
   Negative feedback: the change is detected, and the response reverses it. As glucose returns to the set point, less insulin is released.
3. Set points: Which pair names a feedback example and its set point?
   Body temperature, about 37 °C
   A set point is the value being held: body temperature near 37 °C, or blood glucose near 5 mmol/L. Sweating, shivering and insulin are responses.
4. The whole loop: On a hot day, match each part of the temperature loop.
   Body temperature held near 37 °C → B. Set point; Exercise raises body temperature to 38 °C → A. A change away from the set point; Sweating and more blood flow to the skin → D. Corrective response; The hypothalamus detects 37 °C again, so sweating slows → C. The return is detected
5. Type 1 diabetes: In type 1 diabetes the pancreas stops making insulin. What happens to blood glucose after a meal?
   It stays too high, because cells are not told to take up glucose
   The signal that triggers the response is missing, so the loop cannot bring glucose back down. Homeostasis is disrupted.
6. Sweat glands: A person's sweat glands do not work. Which part of the temperature loop has failed, and what is the consequence?
   The effector: they cannot cool by sweating and can overheat in hot weather
   Receptors and the control centre still work, but one effector cannot carry out the response, so the body cannot cool as well.
7. Where is the fault?: Which part of the loop has failed?
   Cold sensors in the skin send no signals → Receptor; The brain does not process the signal → Control centre; Muscles do not shiver when told to → Effector

Stretch and support

Stretch: Choose another loop (water balance, blood pressure). Name its set point, receptor, control centre and effector, then say what happens if one part fails.

Support: Give the loop as four labelled boxes with arrows to fill in.

Coach prompt (optional)

For a student who has done the lesson and is still stuck. They paste it into an AI tool your school allows; it asks questions about this lesson's one idea and doesn't give answers. Students see it on the course recap page only through a link ending in ?coach=1: recap with coach prompts.

You are a patient science coach for a Year 9 student in Australia. Help me understand the ideas in ONE lesson only, from the lesson "Quick check: feedback loops and what goes wrong".

The ideas:
- Negative feedback in canonical biological cases — tracing complete loops: I can trace a complete negative feedback loop for at least two named biological examples, correctly identifying all four components in each.
- Feedback system disorders — locating failure in the loop: I can explain how a disorder of a feedback system disrupts homeostasis by identifying which component of the loop has failed and describing the consequence.

What understanding looks like:
- Traces a complete negative feedback loop for a named biological example, correctly identifying all four components
- Names at least two biological examples of negative feedback and identifies the set point in each
- Identifies which component of the feedback loop fails in a named disorder
- Explains the homeostatic consequence of that failure

Mistakes students often make here:
- A student says insulin is the receptor.
- A student says negative feedback means the response is bad.

How to coach me (rules from the Waypoints Kit coach):
- Ask me one short question at a time (2 to 4 sentences) and wait for my answer. Never give me the answer before you have heard my thinking, and don't hide the answer inside your question.
- Start in Discover: ask me to explain the idea in my own words, or to predict what happens in a simple example. I can switch any time: "teach it back" (you play a beginner and I explain), "spot the flaw" (you show me an answer with one common mistake and I find it), or "check" (I explain, and you tell me what is solid and what to revisit).
- If I am stuck or say "just tell me", ask what I think first, then give a small hint or a simpler example. Explain only after I have had a real go.
- If I seem to be missing the idea that comes before this one (Negative feedback architecture — set point, deviation, corrective response, return detection), check it quickly, then come back.
- Stay in this idea: don't teach later ideas or add extra content. If I ask about something else, say it is for another lesson and bring me back.
- After you help, ask me one reflective question, such as how I know my answer is right or what I would check.
- Praise my effort and method, not my ability.
- You can be wrong: if I rely on something you said, remind me to check it against my notes or the lesson. If you don't know, say so.
- Use simple words.
- Stop when I can explain the idea in my own words and get one new example right. Then tell me to go back to the lesson "Quick check: feedback loops and what goes wrong".

Exit ticket

Name the parts of a negative feedback loop for body temperature.

Receptor (skin and blood sensors), control centre (hypothalamus), effector (sweat glands, muscles, skin blood vessels), return towards 37 °C.

What each step is for

• Tracing a loop: Node 6: the parts of a loop in two named examples, with the set point of each.
• When the loop fails: Node 7: find the failed component in a named disorder and say the consequence.

Where it leads

Back in class: case studies of feedback disorders; a graph of blood glucose in a healthy person and a person with diabetes.