Bacteria having a tuft of flagella at both ends are called

Options

A. Peritrichous
B. Bitrichous
C. Amphitrichous
D. Atrichous.

Answer

**Step-by-Step Solution:**

1. **Understand the Types of Flagellation in Bacteria:**
- Bacteria can have different arrangements of flagella, which are structures used for movement. The main types of flagellation include:
- Monotrichous: A single flagellum at one end.
- Amphitrichous: A tuft of flagella at both ends.
- Lophotrichous: A tuft of flagella at one end.
- Peritrichous: Flagella distributed all over the surface.
- Atrichous: No flagella present.

2. **Identify the Key Terms:**
- The question specifically asks for bacteria that have a tuft of flagella at both ends. This description matches the term "amphitrichous."

3. **Analyze the Options:**
- Peritrichous: Incorrect, as it refers to flagella distributed over the entire surface.
- Bitrichous: Not a standard term used in flagellation classification.
- Amphitrichous: Correct, as it describes bacteria with flagella at both ends.
- Atrichous: Incorrect, as it indicates the absence of flagella.

4. **Select the Correct Answer:**
- Based on the definitions and the analysis of the options, the correct answer is **amphitrichous**.

**Final Answer:**
Bacteria having a tuft of flagella at both ends are called **amphitrichous**.

---