Which of the following diagrams correctly represents an energy pyramid in a living system?

• A. A rectangle with equal-sized sections for producers, primary consumers, and secondary consumers.
• B. A pyramid with a narrow base representing producers and a broad top representing tertiary consumers.
• C. A pyramid with a broad base representing producers and progressively narrower tiers for primary, secondary, and tertiary consumers.
• D. An inverted pyramid with the largest section at the top for tertiary consumers and the smallest at the bottom for producers.

Answer: (C)

Verified step by step guidance

1. Understand the concept of an energy pyramid: An energy pyramid represents the flow of energy through different trophic levels in an ecosystem. Energy decreases as it moves up the pyramid due to energy loss (e.g., heat) at each level.
2. Identify the trophic levels: Producers (autotrophs) form the base of the pyramid as they capture energy from the sun through photosynthesis. Primary consumers (herbivores) feed on producers, secondary consumers (carnivores) feed on primary consumers, and tertiary consumers feed on secondary consumers.
3. Recognize the energy distribution: The base of the pyramid (producers) contains the most energy because they directly harness energy from the sun. As energy moves up the pyramid, only a fraction (approximately 10%) is transferred to the next level, resulting in progressively smaller tiers.
4. Evaluate the given diagrams: A correct energy pyramid should have a broad base for producers and narrower tiers for primary, secondary, and tertiary consumers, reflecting the decreasing energy availability at higher trophic levels.
5. Conclude that the correct representation is: 'A pyramid with a broad base representing producers and progressively narrower tiers for primary, secondary, and tertiary consumers,' as this accurately reflects the energy flow and loss in a living system.