IGCSE Biology glossary
Pyramid of biomass
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
A diagram showing the total dry mass of organisms at each trophic level in a food chain at a given time. Pyramids of biomass are almost always pyramid-shaped, with the greatest biomass at the producer level and decreasing biomass at each successive level.
What to include in an exam answer
Pyramids of biomass are more reliable than pyramids of numbers because they account for organism size. They are almost always true pyramids. Use dry mass (not wet mass) to avoid variation due to water content.
Example in context
Explain why a pyramid of biomass is usually pyramid-shaped (2 marks): Energy is lost at each trophic level through respiration, heat and waste. Therefore less energy is available to build biomass at each successive level, so the biomass decreases.
Related syllabus topic
Organisms & their environment