IGCSE Biology glossary
Fibre
Biology editorial review is supported by the named review panel. Reviewer participation may vary by guide. Checked against Cambridge IGCSE Biology 0610 (2026–2028); last reviewed August 2026.
Definition
Indigestible plant material (mainly cellulose) in the diet that adds bulk to food in the intestine, stimulating peristalsis and helping move food through the digestive system. Also called roughage or dietary fibre.
What to include in an exam answer
Fibre is not digested or absorbed, so do not say it provides 'nutrients'. Its role is to prevent constipation and promote healthy bowel movements by stimulating peristalsis.
Example in context
Explain the importance of fibre in the diet (2 marks): Fibre adds bulk to food in the intestine, which stimulates peristalsis. This helps move food through the gut and prevents constipation.
Related syllabus topic
Human nutrition