How does energy flow through an ecosystem?

How does energy flow through an ecosystem?

• A. Producers (plants) convert energy from the sun, then primary and secondary consumers, with energy decreasing at each transfer; some energy becomes heat.
• B. Energy increases as you move up trophic levels.
• C. Only producers use energy; consumers do not.
• D. Decomposers supply all energy.

Answer: (D)

Energy in ecosystems comes from the sun and is captured by producers through photosynthesis, converting light energy into chemical energy stored in organic molecules. Primary producers are then eaten by herbivores (primary consumers), which in turn are eaten by other consumers. At every transfer, most of that energy is used for the organisms’ metabolic processes or released as heat, so only a portion remains to fuel the next trophic level. Decomposers play a recycling role: they break down dead matter and waste, releasing stored chemical energy, but they don’t create new energy for the system. Energy thus moves through the ecosystem in one direction from sun to producers to consumers, diminishing at each step as heat is produced.

Energy in ecosystems comes from the sun and is captured by producers through photosynthesis, converting light energy into chemical energy stored in organic molecules. Primary producers are then eaten by herbivores (primary consumers), which in turn are eaten by other consumers. At every transfer, most of that energy is used for the organisms’ metabolic processes or released as heat, so only a portion remains to fuel the next trophic level. Decomposers play a recycling role: they break down dead matter and waste, releasing stored chemical energy, but they don’t create new energy for the system. Energy thus moves through the ecosystem in one direction from sun to producers to consumers, diminishing at each step as heat is produced.