Describe how the body responds when blood glucose concentration falls below the set point.

Cambridge International IGCSE Biology (0610) — 14.4 Homeostasis · Describe · 4 marks · View as Markdown

Written & reviewed by James Millett — Biology (Imperial College London), PGCE Science (University of Cambridge).

A student skips breakfast and goes for a long run. By the end of the run, their blood glucose concentration has dropped below the normal set point.

Model answer (4 marks)

The pancreas senses the drop in blood glucose and releases glucagon.
Glucagon stimulates the liver to break down glycogen into glucose.
Glucose is released into the bloodstream, raising glucose concentration towards the set point.
This is a negative‑feedback response that restores the normal level.

Examiner tips

Use the exact terms: pancreas, glucagon, glycogen, liver, negative feedback.
Show the sequence of events in order.
Mention the set point and restoration of normal level.
Keep the answer concise – 4 points only.

Common mistakes

Confusing insulin with glucagon.
Omitting the liver as the site of glycogen breakdown.
Failing to state that the response restores the set point.

Mark scheme (4 marks)

The pancreas detects the fall in blood glucose concentration and secretes glucagon
Glucagon causes the breakdown of glycogen to glucose in the liver
Glucose is released into the blood, raising blood glucose concentration back towards the set point
This is an example of negative feedback, where the change is reversed to restore the set point

Key terms in this question

set point