Peristalsis and Gut Movement

IGCSE Edexcel Biology
2.28 Peristalsis
Key Concept: Peristalsis is the wave-like contraction of gut muscles that moves food along the alimentary canal.

Section A: Definition

1. Define peristalsis. [2]

Section B: Mechanism

2. Explain how circular and longitudinal muscles move food. [3]
3. Explain why peristalsis works even when you are upside down. [2]

Section C: Links

4. State where bile is produced and where it is stored. [2]
Total marks: 9

Mark Scheme

1. Wave-like contractions of muscles that push food along the gut [2]
2. Circular muscles contract behind food and longitudinal muscles shorten the tube ahead, moving the bolus forward [3]
3. Movement is driven by muscle contractions, not gravity [2]
4. Bile is produced in the liver and stored in the gall bladder [2]