How is energy transferred in a food chain?

• A. From producers to primary consumers to higher-level consumers, with energy lost as heat at each stage.
• B. From consumers to producers with energy increasing at each step.
• C. All energy is conserved and fully transferred to the next level.
• D. Energy is created at each step.

Answer: (A)

Energy moves through a food chain from producers to primary consumers to higher-level consumers, with energy lost as heat at each transfer. Plants capture light energy and store it as chemical energy; when animals eat plants, some of that energy becomes new body mass, but much is used for life processes like movement and respiration. As energy moves up another level, even less is available because another portion is used or lost as heat, so the total energy decreases at each step. This unidirectional flow means higher trophic levels have less energy to support biomass. The other statements don’t fit because energy isn’t created at each step, not all energy is transferred, and producers don’t gain energy from consumers.