What happens to most energy as it moves from one trophic level to the next in an ecosystem?

What happens to most energy as it moves from one trophic level to the next in an ecosystem?

• A. It is lost as heat; only a portion is transferred to the next trophic level.
• B. It is stored entirely in the biomass of the next level.
• C. It is recycled back to producers.
• D. It increases in quantity at higher levels.

Answer: (A)

The main idea is that energy transfer between trophic levels is inefficient. When an organism eats, much of the energy it consumes is used for metabolism— fueling respiration, movement, growth, and body heat. This energy is released as heat and is not passed on to the next level. Only a small fraction, often described as about 10%, is stored as biomass and becomes available to the next trophic level. Because of these losses, energy decreases as you move up the food chain, and it isn’t recycled back to producers or accumulated at higher levels.

The main idea is that energy transfer between trophic levels is inefficient. When an organism eats, much of the energy it consumes is used for metabolism— fueling respiration, movement, growth, and body heat. This energy is released as heat and is not passed on to the next level. Only a small fraction, often described as about 10%, is stored as biomass and becomes available to the next trophic level. Because of these losses, energy decreases as you move up the food chain, and it isn’t recycled back to producers or accumulated at higher levels.