Which of the following shows coiled RNA strand and capsomeres?

Options

A. Retrovirus
B. Polio virus
C. Tobacco mosaic virus
D. Measles virus

Answer

To determine which virus shows a coiled RNA strand and capsomeres, we can follow these steps:

### Step 1: Understand the Components
- **Coiled RNA Strand**: This refers to the genetic material of the virus. It can be single-stranded (SS RNA) or double-stranded (DS RNA).
- **Capsomeres**: These are the protein subunits that make up the capsid, which is the outer protective layer of the virus.

### Step 2: Analyze the Options
We have four options to consider:
1. Retrovirus
2. Poliovirus
3. Tobacco Mosaic Virus
4. Measles Virus

### Step 3: Identify the Characteristics of Each Virus
- **Retrovirus**: Contains RNA but is typically not described as coiled; it has a complex structure.
- **Poliovirus**: Has a single-stranded RNA but does not have a coiled structure.
- **Tobacco Mosaic Virus (TMV)**: Known for its coiled single-stranded RNA (SS RNA) and has a rod-shaped structure with capsomeres forming the capsid.
- **Measles Virus**: Contains RNA but is not coiled in the same manner as TMV.

### Step 4: Conclusion
From the analysis, the **Tobacco Mosaic Virus** is the only virus that has a coiled single-stranded RNA and capsomeres.

### Final Answer
The correct answer is **Tobacco Mosaic Virus**.

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