Which type of ecological pyramid shows the number of individuals at each trophic level?

• A. Numbers pyramid
• B. Energy pyramid
• C. Biomass pyramid
• D. Nutrient pyramid

Answer: (A)

The key idea is understanding what each pyramid is counting or measuring. The type that directly shows how many individual organisms occupy each trophic level is the one that maps the number of individuals at each level. In most ecosystems, there are many producers, and fewer herbivores, and even fewer predators, so the chart often widens at the base and narrows upward, reflecting the declining counts as you move up the food chain.

Energy pyramids, by contrast, depict how much energy flows through each level and always show a decrease moving up because energy is lost mainly as heat. Biomass pyramids display the total dry mass of organisms at each level, which can differ from the number of individuals if organisms vary greatly in size. A nutrient pyramid isn’t used to count individuals at trophic levels, so it doesn’t answer this question.