Bacteria are divided into Gram +ve and Gram -ve based on

Options

A. Nature of cell wall
B. Response to staining
C. Plasmids
D. 1 & 2

Answer

**Step-by-Step Solution:**

1. **Understanding the Classification**: Bacteria are classified into two main groups: Gram-positive and Gram-negative. This classification is primarily based on the characteristics of their cell walls and how they respond to a specific staining technique known as Gram staining.

2. **Nature of the Cell Wall**:
- **Gram-positive Bacteria**: These bacteria have a thick peptidoglycan layer in their cell wall. This thick layer is crucial because it retains the crystal violet stain used during the Gram staining process.
- **Gram-negative Bacteria**: In contrast, Gram-negative bacteria have a much thinner peptidoglycan layer. Due to this thin layer, they do not retain the crystal violet stain and instead take up a counterstain, appearing pink.

3. **Gram Staining Process**: The Gram staining process involves several steps:
- First, the bacteria are stained with crystal violet (which is purple).
- Then, iodine is applied, which helps to fix the dye.
- A decolorizer is used next, which washes out the stain from Gram-negative bacteria due to their thin peptidoglycan layer.
- Finally, a counterstain (usually safranin, which is pink) is applied. Gram-positive bacteria remain purple, while Gram-negative bacteria take on the pink color.

4. **Conclusion**: Therefore, the division of bacteria into Gram-positive and Gram-negative is based on the nature of their cell walls (specifically the thickness of the peptidoglycan layer) and their response to Gram staining.

**Final Answer**: Bacteria are divided into Gram-positive and Gram-negative based on the nature of the cell wall and their response to Gram staining.

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