Most characteristic feature of diatoms is :-

Options

A. Pigments
B. Stored food
C. Cell wall
D. Non oxygenic photosynthesis

Answer

**Step-by-Step Solution:**

1. **Understanding Diatoms**: Diatoms are a type of algae that are primarily found in both freshwater and marine environments. They are unicellular organisms.

2. **Identifying Features**: The question asks for the most characteristic feature of diatoms. We need to evaluate the options provided: pigments, stone, food, cell wall, or non-oxygenic photosynthesis.

3. **Evaluating Options**:
- **Pigments**: Diatoms contain pigments such as chlorophyll A and C. However, these pigments are not unique to diatoms as they are found in many other organisms.
- **Stone**: This option is not relevant to diatoms.
- **Food**: Diatoms store food in the form of carbohydrates, which is also common among various organisms.
- **Cell Wall**: The cell wall of diatoms is made up of silica, which is a unique and distinguishing feature. This silicaceous cell wall is highly resistant and contributes to the formation of diatomaceous earth after the diatoms die.
- **Non-Oxygenic Photosynthesis**: Diatoms perform oxygenic photosynthesis, which is a characteristic of many other organisms as well.

4. **Conclusion**: The most distinguishing feature of diatoms is their cell wall, which is made of silica. This feature sets them apart from other algae and organisms.

5. **Final Answer**: The correct option is **cell wall**.

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