Mark the odd one (w.r.t. prions)
(a) CFJ disease
(b) Mad cow disease
(c) Potato leaf roll
(d) Scrapie disease

Options

A. CFJ disease
B. Mad cow disease
C. Potato leaf roll
D. Scrapie disease

Answer

To solve the question "Mark the odd one (w.r.t. prions)", we need to analyze each option in relation to prions.

### Step-by-Step Solution:

1. **Understand Prions**: Prions are infectious agents composed primarily of protein. They are known to cause various neurodegenerative diseases in animals and humans. They do not contain any nucleic acids (DNA or RNA).

2. **Analyze Each Option**:
- **(a) CFJ disease**: This refers to Creutzfeldt-Jakob disease, which is indeed caused by prions.
- **(b) Mad cow disease**: This disease, also known as Bovine Spongiform Encephalopathy (BSE), is caused by prions.
- **(c) Potato leaf roll**: This is a viral disease affecting potatoes, caused by the potato leaf roll virus, not by prions.
- **(d) Scrapie disease**: This is a prion disease that affects sheep and goats.

3. **Identify the Odd One Out**:
- From the analysis, options (a), (b), and (d) are all diseases caused by prions. However, option (c) is caused by a virus and not by prions.

4. **Conclusion**: The odd one out is (c) Potato leaf roll.

### Final Answer:
(c) Potato leaf roll

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