Lichen is a symbiotic association of

Options

A. an alga and a fungus
B. alga and bacteria
C. fungus and bacteriophages
D. bacteria

Answer

**Step-by-Step Solution:**

1. **Understanding Lichen**: Lichen is a unique organism that results from a symbiotic relationship between two different types of organisms. It is important to identify what these organisms are.

2. **Identifying the Components**: The two main components of lichen are:
- **Fungus**: This is the non-photosynthetic partner that cannot produce its own food.
- **Alga (or Cyanobacteria)**: This is the photosynthetic partner that can produce food through photosynthesis.

3. **Nature of the Relationship**: The relationship between the fungus and the alga is mutualistic. This means that both organisms benefit from each other:
- The alga provides food for itself and the fungus through photosynthesis.
- The fungus provides protection and anchorage to the alga.

4. **Evaluating the Options**: Now, let’s look at the options provided:
- Option A: An alga and a fungus (this is correct).
- Option B: Alga and bacteria (incorrect).
- Option C: Fungus and bacteriopatras (incorrect).
- Option D: Bacteria (incorrect).

5. **Conclusion**: Based on the information analyzed, the correct answer is Option A: an alga and a fungus.

**Final Answer**: Lichen is a symbiotic association of an alga and a fungus (Option A).

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