Which of the following is true about the efficiency of energy transfer in an ecosystem?

• A. All energy from producers is eventually consumed by primary consumers.
• B. Energy transfer between trophic levels is nearly 100\% efficient.
• C. Energy efficiency increases as you move up the trophic levels.
• D. On average, only about 10\% of the energy at one trophic level is transferred to the next trophic level.

Answer: (D)

Verified step by step guidance

1. Understand the concept of energy transfer in ecosystems: Energy flows through an ecosystem via trophic levels, starting with producers (plants and other autotrophs) that capture energy from the sun through photosynthesis. This energy is then passed on to consumers (herbivores, carnivores, etc.) in subsequent trophic levels.
2. Recognize the inefficiency of energy transfer: Energy transfer between trophic levels is not 100% efficient. A significant portion of energy is lost as heat, used for metabolic processes, or remains in parts of the organism that are not consumed (e.g., bones, fur).
3. Learn the 10% rule: On average, only about 10% of the energy at one trophic level is transferred to the next level. This means that if producers capture 100 units of energy, only about 10 units are available to primary consumers, and only 1 unit is available to secondary consumers.
4. Evaluate the incorrect statements: The statement 'All energy from producers is eventually consumed by primary consumers' is false because not all energy is consumed; some is lost or remains in unconsumed parts. The statement 'Energy transfer between trophic levels is nearly 100% efficient' is false because energy transfer is highly inefficient. The statement 'Energy efficiency increases as you move up the trophic levels' is false because energy efficiency decreases as you move up the trophic levels.
5. Conclude with the correct answer: The correct statement is 'On average, only about 10% of the energy at one trophic level is transferred to the next trophic level,' which aligns with the 10% rule and the principles of energy transfer in ecosystems.