Infectious RNA particles without protein coat
(a) Have high molecular weight
(b) Were discovered by Alper
(c) Known to cause disease in plants
(d) More than one option is correct

Options

A. Have high molecular weight
B. Were discovered by Alper
C. Known to cause disease in plants
D. More than one option is correct

Answer

To solve the question regarding infectious RNA particles without a protein coat, we need to analyze each option provided:

1. **Understanding the Question**: The question asks about infectious RNA particles that lack a protein coat. These particles are known as viroids.

2. **Analyzing Option (a)**:
- **Statement**: "Have high molecular weight"
- **Evaluation**: Viroids are known to have a low molecular weight, not high. Therefore, this statement is **incorrect**.

3. **Analyzing Option (b)**:
- **Statement**: "Were discovered by Alper"
- **Evaluation**: The discovery of viroids is attributed to Theodor O. Diener, not Alper. Thus, this statement is also **incorrect**.

4. **Analyzing Option (c)**:
- **Statement**: "Known to cause disease in plants"
- **Evaluation**: Viroids are indeed known to cause diseases in various plants. This statement is **correct**.

5. **Analyzing Option (d)**:
- **Statement**: "More than one option is correct"
- **Evaluation**: Since only option (c) is correct, this statement is **incorrect**.

6. **Conclusion**: Based on the analysis, the only correct option is (c), which states that viroids are known to cause disease in plants.

**Final Answer**: (c) Known to cause disease in plants.

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