Name the organisms which do not derive energy directly/indirectly from sun.

Options

A. Chemosynthetic bacteria
B. Symbiotic bacteria
C. Pathogenic bacteria
D. Moulds

Answer

To answer the question regarding organisms that do not derive energy directly or indirectly from the sun, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding the Question**: The question asks for organisms that do not rely on sunlight for energy. This includes both direct and indirect dependence on solar energy.

2. **Identifying Organisms**:
- **Chemosynthetic Bacteria**: These are the primary organisms that do not rely on sunlight. They derive energy from the oxidation of inorganic molecules (like hydrogen sulfide or ammonia) and convert these into organic compounds. They are often found in extreme environments such as deep-sea vents.
- **Symbiotic Bacteria**: While some symbiotic bacteria can be involved in processes that do not directly rely on sunlight, they often depend on their host organisms, which may ultimately derive energy from sunlight. For example, Rhizobium bacteria in root nodules of legumes depend on the plant for nutrients.
- **Pathogenic Bacteria**: These bacteria can also be dependent on their host organisms for energy, which may ultimately derive from sunlight. Thus, they do not fit the criteria of being independent from sunlight.
- **Molds**: Molds are fungi that typically require organic matter for energy, which can be derived from plants that rely on sunlight. Therefore, they also do not meet the criteria.

3. **Conclusion**: Based on the analysis, the only organisms that do not derive energy from the sun are **chemosynthetic bacteria**.

### Final Answer:
The organisms that do not derive energy directly or indirectly from the sun are **chemosynthetic bacteria**.

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