What type of nucleic acid is found in the viral pathogen that causes mottling and leaf discoloration in the Nicotiana group of plants ?

Options

A. Double stranded RNA
B. Double stranded DNA
C. Single stranded RNA
D. Single stranded DNA

Answer

To determine the type of nucleic acid found in the viral pathogen that causes mottling and leaf discoloration in the Nicotiana group of plants, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Pathogen**: The question refers to a viral pathogen that causes mottling and leaf discoloration specifically in the Nicotiana group of plants. This group includes tobacco plants, which are commonly affected by various viral infections.

2. **Understand the Types of Nucleic Acids in Viruses**: Viruses can contain different types of nucleic acids:
- Double-stranded RNA (dsRNA)
- Double-stranded DNA (dsDNA)
- Single-stranded RNA (ssRNA)
- Single-stranded DNA (ssDNA)

3. **Focus on Plant Viruses**: In plant viruses, the most common types of nucleic acids are single-stranded RNA (ssRNA) and double-stranded RNA (dsRNA). Double-stranded DNA viruses are less common in plants.

4. **Recall Specific Viruses**: The question hints at a specific viral infection that causes mottling in Nicotiana plants. One well-known virus that causes such symptoms is the Tobacco Mosaic Virus (TMV), which is known to have single-stranded RNA as its genetic material.

5. **Choose the Correct Answer**: Based on the information that TMV and similar viruses affecting Nicotiana plants contain single-stranded RNA, we can conclude that the nucleic acid type in the viral pathogen is single-stranded RNA.

### Final Answer:
The type of nucleic acid found in the viral pathogen that causes mottling and leaf discoloration in the Nicotiana group of plants is **Option C: single-stranded RNA**.

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