Which of the following cycles describes the movement of nutrients through living organisms and the environment?

• A. Nutrient cycle
• B. Energy cycle
• C. Water cycle
• D. Carbon cycle

Answer: (A)

The movement of nutrients through living organisms and the environment is best captured by the nutrient cycle. This cycle encompasses the flow and transformation of essential elements that organisms need to thrive, such as nitrogen, phosphorus, and potassium. These nutrients are taken up by plants from the soil, transferred through the food web as animals consume plants and each other, and eventually returned to the environment through decay and decomposition when organisms die. This cyclic process ensures that nutrients are recycled, making them available for new growth and sustaining ecosystems.

While the energy cycle focuses on the flow of energy through different trophic levels—from producers to consumers and decomposers—the water cycle specifically addresses the movement of water in various forms and stages (evaporation, condensation, precipitation). The carbon cycle, on the other hand, primarily tracks how carbon is exchanged among the atmosphere, biosphere, oceans, and geological formations, concentrating on carbon-containing compounds. Each of these cycles is vital for ecosystem functioning, yet the nutrient cycle specifically encompasses the overall movement of essential nutrients among organisms and their environment.