The bacteria which lacks flagella and moves by gliding are included in

Options

A. Rickettsiae
B. Eubacteria
C. Spirochaete
D. Myxobacteria.

Answer

**Step-by-Step Solution:**

1. **Understand the Question**: The question asks about bacteria that lack flagella and move by gliding. This indicates that we are looking for a specific group of bacteria that do not have the typical appendages (flagella) used for movement.

2. **Define Flagella**: Flagella are cellular appendages that aid in locomotion. They are typically found in many types of bacteria and are crucial for their movement.

3. **Identify the Term for Bacteria Without Flagella**: Bacteria that do not have flagella are referred to as "atrichous." This means they lack flagella and rely on other means for movement.

4. **Consider the Movement Mechanism**: Since the question specifies that the bacteria move by gliding, we need to identify which group of bacteria is known for this type of movement. Gliding movement can occur through the secretion of mucilage.

5. **Evaluate the Options**:
- **Option 1: Rickettsia** - These are typically flagellated and do not exhibit gliding.
- **Option 2: Eubacteria** - This is a broad category that includes many bacteria, some of which have flagella.
- **Option 3: Spirochaete** - These bacteria are known for their unique movement using flagella.
- **Option 4: Myxobacteria** - These bacteria are known to be atrichous (lack flagella) and move by gliding.

6. **Conclusion**: Based on the characteristics of the groups mentioned, the correct answer is **Myxobacteria**, as they are the bacteria that lack flagella and move by gliding.

**Final Answer**: The bacteria which lacks flagella and moves by gliding are included in **Myxobacteria**.

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