Among the following biogeochemical cycles, which one does not have losses due to respiration?

Options

A. (a) Phosphorus
B. (b) Nitrogen
C. (c) Sulphur
D. (d) All of the above

Answer

To solve the question regarding which biogeochemical cycle does not have losses due to respiration, we will follow these steps:

### Step-by-Step Solution:

1. **Understand Biogeochemical Cycles**:
- Biogeochemical cycles are pathways through which essential elements of living matter are circulated in the ecosystem. They can be categorized into two types: gaseous cycles and sedimentary cycles.

2. **Identify the Types of Cycles**:
- **Gaseous Cycles**: These cycles have their main reservoir in the atmosphere. Examples include the nitrogen, carbon, oxygen, and water cycles.
- **Sedimentary Cycles**: These cycles have their main reservoir in the earth's crust (lithosphere). Examples include the phosphorus, sulfur, calcium, and iron cycles.

3. **Analyze the Role of Respiration**:
- Respiration is a process through which living organisms convert organic substances into energy, releasing carbon dioxide and water as byproducts. This process primarily involves elements that are part of gaseous cycles.

4. **Evaluate Each Element**:
- **Phosphorus and Sulfur**: These elements are part of sedimentary cycles and do not exist in a gaseous form. Therefore, they are not involved in respiration and do not have losses due to respiration.
- **Nitrogen**: While nitrogen is part of a gaseous cycle, it is not directly usable by living organisms in its atmospheric form (N2). It must be converted into a usable form (organic nitrogen) through nitrogen fixation. Hence, it also does not have losses due to respiration.

5. **Conclusion**:
- Since phosphorus and sulfur (sedimentary cycles) and nitrogen (gaseous cycle but not usable in respiration) do not have losses due to respiration, the correct answer to the question is **D. All of the above**.