Viroids are different from viruses w.r.t :

Options

A. Size and cell type
B. Size and structural components
C. Structural organisation and non-infectious nature
D. Multiplication and cellular organisation

Answer

To answer the question about how viroids differ from viruses, we can break down the differences into several key aspects:

### Step-by-Step Solution:

1. **Definition of Viroids and Viruses**:
- **Viruses** are obligate parasites that can contain either DNA or RNA as their genetic material. They are typically surrounded by a protein coat known as a capsid.
- **Viroids**, on the other hand, are much simpler entities that consist solely of single-stranded RNA without a protein coat.

2. **Size Comparison**:
- Viroids are significantly smaller than viruses. This is because they lack the additional structural components (like the capsid) that viruses possess.

3. **Structural Components**:
- Viruses have a complex structure that includes genetic material (either DNA or RNA) and a protective protein coat (capsid).
- Viroids do not have a capsid; they are just free, infectious RNA molecules. This absence of a protein coat is a major distinguishing feature.

4. **Molecular Weight**:
- The RNA in viroids has a low molecular weight compared to the genetic material found in viruses, which can vary widely in size and complexity.

5. **Infectious Nature**:
- Both viroids and viruses are infectious, meaning they can cause diseases in their respective hosts. Therefore, this aspect does not serve to differentiate them.

6. **Multiplication**:
- Both viroids and viruses replicate within host cells, so there is no significant difference in their multiplication processes.

7. **Conclusion**:
- The primary differences between viroids and viruses lie in their size and structural components. Viroids are smaller and lack a protein coat, while viruses are larger and have a more complex structure.

### Final Answer:
Viroids are different from viruses with respect to size and structural components.

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