On the basis of ecology which is not essenttial for self sustaining ecosystem:

Options

A. Producer
B. Macro-consumers
C. Micro-consumers
D. All of above.

Answer

To determine which component is not essential for a self-sustaining ecosystem, we need to analyze the roles of producers, macro-consumers, and micro-consumers within an ecosystem.

### Step-by-Step Solution:

1. **Understanding Ecosystem Components**:
- An ecosystem consists of biotic (living) and abiotic (non-living) components. The biotic components include producers, consumers (macro and micro), and decomposers.

2. **Role of Producers**:
- Producers, primarily plants, are essential because they create their own food through photosynthesis. They form the base of the food chain and are crucial for energy flow in the ecosystem. Without producers, there would be no energy source for consumers.

3. **Role of Micro-Consumers**:
- Micro-consumers, or decomposers (like bacteria and fungi), play a vital role in breaking down dead organic matter. They recycle nutrients back into the ecosystem, which is essential for the sustainability of the ecosystem. Without them, the ecosystem would accumulate dead matter, leading to a collapse.

4. **Role of Macro-Consumers**:
- Macro-consumers include herbivores, carnivores, and omnivores. While they are important for maintaining the balance of the ecosystem, they are not strictly essential for the ecosystem to sustain itself. An ecosystem can survive without macro-consumers, as long as producers and micro-consumers are present.

5. **Conclusion**:
- Based on the analysis, the component that is not essential for a self-sustaining ecosystem is **macro-consumers**. Therefore, the correct answer is that macro-consumers are not essential.

### Final Answer:
**Macro-consumers are not essential for a self-sustaining ecosystem.**