Which of the following statements is not associated with pyramids of energy?

Step 1: Analyze the question We need the statement that is NOT associated with pyramids of energy. Three options describe real features of energy pyramids, and one describes something else.

Step 2: The concept A pyramid of energy shows the amount of energy (usually in kJ/m²/year) at each trophic level of a food chain. Its key features are:

• It is always upright, because energy is lost as heat at each transfer (about 10% passes on).
• It allows the efficiency of energy transfer between trophic levels to be studied.
• It allows ecosystems to be compared, because all levels are measured in the same unit (energy).
• It gives a more accurate comparison of trophic levels than pyramids of numbers or biomass, because it is not affected by the size of the organisms or by seasonal changes.

Step 3: Check each option

• A. True. Energy pyramids show how much energy passes from one level to the next.
• B. True. Energy units are standard, so different ecosystems can be compared.
• C. True. Energy pyramids are more accurate than numbers or biomass pyramids.
• D. Not associated. Representing the numbers of organisms at each trophic level describes a pyramid of numbers, not a pyramid of energy.

Step 4: Answer The statement that does not belong to pyramids of energy is D.

Exam tip: Match each pyramid to its unit:

• Numbers: count of organisms (can be inverted)
• Biomass: dry mass (can be inverted, e.g. in the ocean)
• Energy: kJ (always upright)

If a statement mentions "numbers", think pyramid of numbers.