Bdellovibrios is

Options

A. Virus
B. Viroid
C. Prion
D. Bacterium.

Answer

**Step-by-Step Solution:**

1. **Understanding Bdellovibrios**: Bdellovibrios is a genus of bacteria. It is important to recognize that it belongs to the group of organisms known as bacteria.

2. **Characteristics of Bdellovibrios**: This genus is characterized by its comma shape and is classified as gram-negative. Gram-negative bacteria do not retain the crystal violet stain used in the Gram staining procedure, which is a key characteristic for identification.

3. **Aerobic Nature**: Bdellovibrios are obligate aerobes, meaning they require oxygen to survive and cannot thrive in anaerobic (absence of oxygen) conditions.

4. **Predatory Behavior**: One of the notable features of Bdellovibrios is their ability to prey on other gram-negative bacteria. They feed on biopolymers, including proteins and nucleic acids, which makes them unique among bacteria.

5. **Conclusion**: Based on the characteristics and behavior of Bdellovibrios, it is classified as a bacterium. Therefore, the correct answer to the question is that Bdellovibrios is a bacterium.

**Final Answer**: Bdellovibrios is a bacterium.

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