Which statement accurately describes energy transfer in an ecosystem's energy pyramid?

Which statement accurately describes energy transfer in an ecosystem's energy pyramid?

• A. Only a portion of energy at one trophic level is stored in the next; most is lost as heat.
• B. Energy is completely transferred to the next trophic level.
• C. Energy doubles at each level.
• D. Energy remains the same across levels.

Answer: (C)

The main idea is how energy moves through an ecosystem and why it gets smaller at higher levels. Energy starts with the sun and is captured by producers, stored as chemical energy in biomass. When organisms at one level are eaten, only a portion of that energy becomes new biomass in the next level; the rest powers the eater’s metabolism, movement, and growth, and is released as heat. Because of this loss at each transfer, energy declines as you go up the pyramid, not increases. A common rule of thumb is about 10% of the energy at one level is transferred to the next, with the remaining 90% lost as heat or used for life processes. So energy doubling at each level isn’t how ecosystems work; energy is lost, not created or amplified, as it moves up the pyramid.

The main idea is how energy moves through an ecosystem and why it gets smaller at higher levels. Energy starts with the sun and is captured by producers, stored as chemical energy in biomass. When organisms at one level are eaten, only a portion of that energy becomes new biomass in the next level; the rest powers the eater’s metabolism, movement, and growth, and is released as heat. Because of this loss at each transfer, energy declines as you go up the pyramid, not increases. A common rule of thumb is about 10% of the energy at one level is transferred to the next, with the remaining 90% lost as heat or used for life processes. So energy doubling at each level isn’t how ecosystems work; energy is lost, not created or amplified, as it moves up the pyramid.