Which of the following best describes how energy flows through a food web?

• A. Energy flows in one direction, from producers to various levels of consumers.
• B. Most energy is lost as heat at each trophic level.
• C. Decomposers create new energy for the ecosystem.
• D. Energy is recycled between organisms and never lost from the ecosystem.

Answer: (A)

Verified step by step guidance

1. Step 1: Begin by understanding the concept of energy flow in ecosystems. Energy originates from the sun and is captured by producers (autotrophs) through photosynthesis, forming the base of the food web.
2. Step 2: Recognize that energy flows in one direction through the food web, starting with producers and moving to primary consumers (herbivores), secondary consumers (carnivores or omnivores), and higher-level consumers.
3. Step 3: Understand that at each trophic level, a significant portion of energy is lost as heat due to metabolic processes, such as respiration. This is explained by the second law of thermodynamics.
4. Step 4: Clarify the role of decomposers in the ecosystem. Decomposers break down dead organisms and recycle nutrients, but they do not create new energy. Energy cannot be recycled; it is continuously lost as heat.
5. Step 5: Conclude that energy is not recycled between organisms. Instead, it flows in one direction and diminishes at each trophic level, making the statement 'Energy flows in one direction, from producers to various levels of consumers. Most energy is lost as heat at each trophic level.' the correct description.