Which one is smallest among the following

Options

A. TMV
B. Bacteriophage
C. Neurospora
D. E. coli

Answer

To determine which organism is the smallest among the given options (TMV, bacteriophage, Neurospora, and E. coli), we can analyze the size of each option step by step:

### Step 1: Analyze TMV (Tobacco Mosaic Virus)
- TMV is a virus that causes mosaic disease in tobacco plants.
- The length of TMV is approximately **300 nanometers**.

### Step 2: Analyze Bacteriophage
- A bacteriophage is a type of virus that infects bacteria.
- The size of a typical bacteriophage is approximately **200 nanometers**.
- Since this is smaller than TMV, we note this down.

### Step 3: Analyze Neurospora
- Neurospora is a genus of fungi, specifically a multicellular organism belonging to the Ascomycetes.
- Fungi, including Neurospora, are generally much larger than viruses.
- Therefore, we can conclude that Neurospora is not the smallest among the options.

### Step 4: Analyze E. coli (Escherichia coli)
- E. coli is a type of bacteria.
- The size of E. coli is approximately **2 micrometers** (or 2000 nanometers).
- This size is significantly larger than both TMV and bacteriophage.

### Conclusion
- After comparing the sizes:
- TMV: 300 nanometers
- Bacteriophage: 200 nanometers
- Neurospora: larger than viruses
- E. coli: 2000 nanometers
- The smallest organism among the options is the **bacteriophage** at **200 nanometers**.

### Final Answer
**Bacteriophage is the smallest among the given options.**

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