Question

an energy pyramid is given. which statement best explains why the energy pyramid is narrower at the top? tertiary consumer secondary consumer primary consumer producer image of energy pyramid organisms at the higher levels have less energy available to them than organisms at the lower levels. organisms at the higher levels use a narrower range of environmental resources than organisms at the lower levels. organisms at the higher levels are more efficient at utilizing energy from sunlight than organisms at the lower levels. organisms at the higher levels are larger and require less energy per unit of body mass than organisms at the lower levels.

Explanation:

In an energy pyramid, energy transfer between trophic levels is inefficient (about 10% energy is passed on). Producers (lower level) capture energy (e.g., from sunlight), and as we move up (to primary, secondary, tertiary consumers), each level has less energy available because most energy is lost as heat, used for metabolism, etc.

• Option 1: Correct. Higher trophic level organisms have less energy available (due to 10% transfer rule), so the pyramid narrows (fewer organisms or less biomass) as energy decreases.
• Option 2: Higher levels don’t use a narrower resource range to explain energy pyramid shape; resource range is not the key here.
• Option 3: Higher level organisms (consumers) don’t use sunlight (producers do), so this is incorrect.
• Option 4: Higher level organisms are usually smaller or have higher energy per unit mass (or not; the energy availability, not body mass efficiency, explains the pyramid’s shape).

Answer:

The correct option is: "Organisms at the higher levels have less energy available to them than organisms at the lower levels." (the first option among the choices, corresponding to the statement about less energy at higher levels)