Explain how the body detects and responds to a rise in blood glucose concentration after a meal, and describe what happens when blood glucose levels return to normal. In your answer, name the organ and hormone involved.

Eduqas A-Level Biology — 4.3 Variation and evolution · Explain · 5 marks · View as Markdown

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

After eating a meal containing carbohydrates, the blood glucose concentration rises above the normal optimum level.

Model answer (5 marks)

The pancreas detects the rise in blood glucose concentration
The pancreas secretes insulin into the blood
Insulin causes cells to take up more glucose from the blood
Insulin causes the liver to convert glucose into glycogen for storage
Blood glucose concentration falls back to the normal level, so less insulin is secreted – negative feedback

Examiner tips

  • Use the exact terms: pancreas, insulin, negative feedback
  • Show the sequence: detection → secretion → action → return to normal
  • Keep each point brief and separate

Common mistakes

  • Confusing glucagon with insulin
  • Omitting the pancreas as the detecting organ
  • Not mentioning negative feedback

Mark scheme (5 marks)

  1. The pancreas detects the rise in blood glucose concentration
  2. The pancreas secretes / releases insulin into the blood
  3. Insulin causes cells to take up more glucose from the blood
  4. Insulin causes the liver to convert glucose into glycogen for storage
  5. Blood glucose concentration falls back to the normal / optimum level, so less insulin is secreted — this is negative feedback

Key terms in this question

blood glucose concentration

Related

More Variation and evolution questions

▶ Try answering this question with AI marking (free) →