On the basis of different shapes, bacteria are grouped under

Options

A. 2 Categories
B. 3 Categories
C. 5 Categories
D. 4 Categories

Answer

To answer the question "On the basis of different shapes, bacteria are grouped under," we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Bacteria Classification**: Bacteria are classified based on various criteria, one of which is their shape.

2. **Identifying the Shapes**: There are four primary shapes in which bacteria can be categorized:
- **Coccus**: These are spherical-shaped bacteria. They appear round and can exist as single cells or in clusters.
- **Bacillus**: These are rod-shaped bacteria. They resemble elongated cylinders and can also be found in chains or singly.
- **Vibrio**: These are comma-shaped bacteria. They have a curved rod shape, resembling a comma.
- **Spirillum**: These are spiral-shaped bacteria. They have a corkscrew shape and can be quite long and flexible.

3. **Categorizing Bacteria**: Based on the shapes identified, we can categorize bacteria into four main groups:
- Spherical (Coccus)
- Rod (Bacillus)
- Comma (Vibrio)
- Spiral (Spirillum)

4. **Conclusion**: Therefore, on the basis of different shapes, bacteria are grouped under these four categories: Coccus, Bacillus, Vibrio, and Spirillum.

### Final Answer:
On the basis of different shapes, bacteria are grouped under Coccus, Bacillus, Vibrio, and Spirillum.