On a global scale, energy _____ ecosystems whereas chemical elements _____ ecosystems.

• A. is recycled within; flow through
• B. is created in; are destroyed in
• C. remains constant in; are lost from
• D. flows through; are recycled within

Answer: (D)

Verified step by step guidance

1. Step 1: Understand the key concepts of energy flow and chemical cycling in ecosystems. Energy flows through ecosystems, meaning it enters as sunlight, is converted by producers into chemical energy, and eventually leaves the ecosystem as heat. Chemical elements, on the other hand, are recycled within ecosystems through processes like decomposition and nutrient cycling.
2. Step 2: Analyze the options provided in the problem. Each option describes a relationship between energy and chemical elements in ecosystems. Compare these descriptions to the scientific understanding of energy flow and chemical cycling.
3. Step 3: Eliminate incorrect options based on scientific principles. For example, energy is not recycled within ecosystems; it flows through them. Similarly, chemical elements are not lost from ecosystems; they are recycled within them.
4. Step 4: Identify the correct answer based on the analysis. The correct description is that energy flows through ecosystems, and chemical elements are recycled within ecosystems.
5. Step 5: Reflect on the importance of these processes. Energy flow and chemical cycling are fundamental to ecosystem function, supporting life and maintaining balance in the environment.