Which of the following best describes the amount of matter that cycles through a food web in an ecosystem?

• A. Matter is created at each trophic level.
• B. Matter is recycled and reused within the ecosystem.
• C. Matter flows in one direction and is not recycled.
• D. Matter is lost as heat at each trophic level.

Answer: (B)

Verified step by step guidance

1. Understand the concept of matter cycling in an ecosystem: Matter refers to physical substances like carbon, nitrogen, and water that are essential for life. These elements are part of biogeochemical cycles and are reused within ecosystems.
2. Recognize that matter is not created or destroyed in biological systems. This principle is based on the law of conservation of matter, which states that matter can change forms but is not created or lost.
3. Analyze the options provided: The first option, 'Matter is created at each trophic level,' is incorrect because matter cannot be created. The third option, 'Matter flows in one direction and is not recycled,' is also incorrect because matter is continuously recycled in ecosystems. The fourth option, 'Matter is lost as heat at each trophic level,' is incorrect because heat loss applies to energy, not matter.
4. Focus on the correct option: 'Matter is recycled and reused within the ecosystem.' This aligns with the concept of nutrient cycling, where matter moves through the food web and is eventually returned to the environment through processes like decomposition.
5. Conclude that the correct answer is based on the principle that matter is recycled and reused within ecosystems, ensuring the continuity of life processes.