Which of the following is the odd one out ?

Options

A. Mitochondria
B. Chloroplast
C. Bacteriophage
D. Tobacco mosaic virus

Answer

To determine which of the following is the odd one out, we need to analyze each option based on their characteristics:

1. **Mitochondria**:
- It is a membrane-bound organelle.
- Found in eukaryotic cells.
- Known as the powerhouse of the cell as it releases energy.
- Contains its own circular DNA.

2. **Chloroplast**:
- It is also a membrane-bound organelle.
- Found in eukaryotic cells.
- The site of photosynthesis.
- Contains its own DNA, similar to mitochondria.

3. **Bacteriophage**:
- This is a virus that infects bacteria.
- It has its own DNA.
- It is not a membrane-bound organelle and is not found in eukaryotic cells.

4. **Tobacco Mosaic Virus**:
- This is a virus that infects tobacco plants.
- It is a single-stranded RNA virus, meaning it does not possess DNA.

Now, let's summarize the key points:
- Mitochondria and chloroplasts are both membrane-bound organelles found in eukaryotic cells and contain DNA.
- Bacteriophage is a virus that has DNA but is not a eukaryotic organelle.
- Tobacco Mosaic Virus is a virus that has RNA instead of DNA.

**Conclusion**: The odd one out is the **Tobacco Mosaic Virus** because it is a single-stranded RNA virus, while the other three options (mitochondria, chloroplast, and bacteriophage) contain DNA.

### Step-by-Step Solution:
1. Identify the characteristics of each option.
2. Note the presence of DNA in mitochondria, chloroplast, and bacteriophage.
3. Recognize that tobacco mosaic virus is a single-stranded RNA virus and lacks DNA.
4. Conclude that tobacco mosaic virus is the odd one out.