________ are very good pollution indicators and act as poineer community in ecological succession

Options

A. Lichens
B. Bacteria
C. Algae
D. Mosses

Answer

**Step-by-Step Solution:**

1. **Understanding the Question**: The question asks for an organism that serves as a good pollution indicator and acts as a pioneer community in ecological succession.

2. **Identifying Key Terms**:
- **Pollution Indicators**: Organisms that can indicate the level of pollution in an environment.
- **Pioneer Community**: The first organisms to colonize a barren or disturbed area during ecological succession.

3. **Considering Organisms**: Among various organisms, we need to identify which one fits both criteria of being a pollution indicator and a pioneer species.

4. **Analyzing Lichens**:
- Lichens are a symbiotic association between fungi and algae.
- The algal component (called the icobiant) performs photosynthesis, while the fungal component (called the mycobiant) provides structure and protection.

5. **Pollution Sensitivity**: Lichens are sensitive to air pollution, particularly sulfur dioxide. They do not thrive in polluted environments, making them excellent indicators of air quality.

6. **Role in Ecological Succession**: Lichens are often among the first organisms to colonize bare rock or disturbed areas, thus acting as pioneer species. They help in soil formation by breaking down the substrate.

7. **Conclusion**: Based on the above analysis, the answer to the question is "lichens".

**Final Answer**: Lichens are very good pollution indicators and act as a pioneer community in ecological succession.

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