What happens to energy as it moves from producers to higher trophic levels in a food chain?

• A. It decreases at each step.
• B. It increases at each step.
• C. It stays the same.
• D. It disappears.

Answer: (A)

Energy moves through a food chain, but not all of it goes along to the next level. Plants capture energy from the sun and store it as chemical energy. When animals eat plants (or other animals), only a portion of that energy ends up in the eater’s body as new tissue. The rest is used for life activities like moving, growing, and repairing, and is released as heat or exits as waste. Each time you move to the next level, less energy is available to support the organisms there. That’s why energy decreases at each step. For example, if the plants have 100 units of energy, only about 10 might be passed to herbivores, and only about 1 to top carnivores, with the rest lost as heat or used up.