Question

Which of the following is a suitable example of sedimentary cycle?

• A. Carbon cycle
• B. Oxygen cycle
• C. Nitrogen cycle
• D. Phosphorous cycle

Hint:

To distinguish between cycle types, ask: "Where is the main reservoir of this element?" If the answer is "in the air," it's a gaseous cycle. If the answer is "in the rocks/soil," it's a sedimentary cycle. Phosphorus is the key example of a sedimentary cycle.

Answer 1

The Correct Option is D

Step 1: Understanding the Concept:
Nutrient cycles (or biogeochemical cycles) can be broadly classified into two types: 1. Gaseous cycles: The main reservoir of the nutrient is the atmosphere or hydrosphere (e.g., nitrogen, carbon, oxygen cycles). 2. Sedimentary cycles: The main reservoir of the nutrient is the lithosphere (soil and rocks) (e.g., phosphorus, sulfur, calcium cycles).

Step 3: Detailed Explanation:
\[\begin{array}{rl} \bullet & \text{(A) Carbon cycle: Has a major atmospheric reservoir (CO\(_2\)) and is considered a gaseous cycle.} \\ \bullet & \text{(B) Oxygen cycle: Has a major atmospheric reservoir (O\(_2\)) and is a gaseous cycle.} \\ \bullet & \text{(C) Nitrogen cycle: Has a major atmospheric reservoir (N\(_2\)) and is a gaseous cycle.} \\ \bullet & \text{(D) Phosphorous cycle: The main reservoir of phosphorus is in rocks and marine sediments. It is released into ecosystems through the slow process of weathering. There is no significant gaseous component to the phosphorus cycle. Therefore, it is a classic example of a sedimentary cycle.} \\ \end{array}\]

Step 4: Final Answer:
The Phosphorous cycle is a suitable example of a sedimentary cycle.