Which cycle describes the movement of phosphorus through rocks, water, and living organisms?

• A. Carbon Cycle
• B. Water Cycle
• C. Nitrogen Cycle
• D. Phosphorus Cycle

Answer: (D)

Phosphorus moves through rocks, water, and living organisms in the phosphorus cycle. Phosphorus starts in rocks as phosphate minerals; weathering releases phosphate into soils and streams, making it available to plants. Plants take it up, and it moves through the food web as animals eat plants and decompose. When organisms die or waste is decomposed, phosphate returns to soil or water and can become buried again, eventually forming sedimentary rock and restarting the cycle. A key point is that phosphorus does not have a meaningful atmospheric phase, so most of its movement is between rocks, water, and organisms rather than through the air. This distinguishes it from cycles like carbon or nitrogen, which involve significant atmospheric components, and from the water cycle, which centers on water itself rather than phosphorus cycling.