In ecosystems, organisms at the highest trophic levels usually contain less collective biomass than the organisms at lower trophic levels because __________.

• A. biomass shrinks as it rises
• B. top-level predators use so much energy to catch their food
• C. producers (for example, plants) tend to be heavier than consumers (for example, birds)
• D. most of the solar energy hitting Earth is reflected back into space
• E. organisms are inefficient at converting the energy they consume into biomass

Answer: (E)

Verified step by step guidance

1. Understand the concept of trophic levels: In an ecosystem, trophic levels represent the hierarchical levels in a food chain, starting with producers at the base and moving up to various levels of consumers.
2. Recognize the energy transfer between trophic levels: Energy is transferred from one trophic level to the next, but this transfer is inefficient. Typically, only about 10% of the energy is passed on to the next level, while the rest is lost as heat or used for metabolic processes.
3. Consider the implications of energy inefficiency: Because of the inefficiency in energy transfer, organisms at higher trophic levels have less energy available to convert into biomass compared to those at lower levels.
4. Relate energy inefficiency to biomass: Since less energy is available at higher trophic levels, these organisms tend to have less collective biomass than those at lower levels, such as producers.
5. Conclude with the correct explanation: The reason organisms at the highest trophic levels contain less collective biomass is due to the inefficiency in converting consumed energy into biomass, not because of the other options provided.