Which of the following diseases in plants is different from the others ?

Options

A. Mosaic formation
B. Leaf rolling and curling
C. Yellowing and in clearing
D. Potato spindle tuber disease

Answer

To determine which disease in plants is different from the others, we need to analyze the options provided in the question. The key is to identify the causes of each disease and see if one stands out.

### Step-by-Step Solution:

1. **Identify the Diseases**:
- The diseases mentioned are: mosaic formation, leaf rolling, curling, yellowing, vein clearing, and potato spindle tuber disease.

2. **Determine the Causes**:
- Mosaic formation, leaf rolling, curling, yellowing, and vein clearing are typically caused by viral infections. These symptoms are often associated with various plant viruses.
- Potato spindle tuber disease, on the other hand, is caused by a viroid, which is a simpler infectious agent than a virus.

3. **Compare the Pathogens**:
- Viruses are acellular entities that require a host to replicate and can have either DNA or RNA as their genetic material.
- Viroids are even simpler, consisting solely of a short strand of RNA without a protein coat.

4. **Identify the Odd One Out**:
- Since all the symptoms except for potato spindle tuber disease are caused by viruses, and potato spindle tuber disease is caused by a viroid, it stands out as the different one.

5. **Conclusion**:
- Therefore, the disease that is different from the others is **potato spindle tuber disease**.

### Final Answer:
**Potato spindle tuber disease is the odd one out.**

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