Which is not a reservoir for phosphorous in phosphorous cycle?

Options

A. Atmosphere
B. Lithosphere
C. Hydorsphere
D. All of the above.

Answer

**Step-by-Step Solution:**

1. **Understanding the Phosphorus Cycle**: The phosphorus cycle is a biogeochemical cycle that describes the movement of phosphorus through the lithosphere, hydrosphere, and biosphere. Phosphorus is a crucial element for living organisms as it is a component of nucleic acids (DNA and RNA), ATP (energy currency of the cell), and phospholipids in cell membranes.

2. **Identifying Phosphorus Reservoirs**: In the phosphorus cycle, the main reservoirs include:
- Rocks and minerals (which contain phosphate ions).
- Soil (where phosphorus is absorbed by plants).
- Water bodies (where phosphorus can be found in dissolved forms).

3. **Examining the Options**: The question asks which of the given options is NOT a reservoir for phosphorus. One of the options provided is "atmosphere."

4. **Analyzing the Atmosphere**: The atmosphere is primarily composed of gases (like nitrogen, oxygen, carbon dioxide, etc.). Unlike carbon and nitrogen cycles, there is no gaseous form of phosphorus that can be found in the atmosphere. Phosphorus does not exist in a gaseous state and is not cycled through the atmosphere.

5. **Conclusion**: Since the atmosphere does not contain phosphorus in any form, it is not a reservoir for phosphorus in the phosphorus cycle. Therefore, the correct answer is the atmosphere.

**Final Answer**: The atmosphere is not a reservoir for phosphorus in the phosphorus cycle.

---