The main difference in Gram (+ve) and Gram (-ve) bacteria resides in their:

Options

A. Differential staining of cell wall
B. Special staining of cell wall
C. Simple staining of cell wall
D. Positive staining of cell wall

Answer

To solve the question regarding the main difference between Gram-positive and Gram-negative bacteria, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding the Question**: The question asks about the main difference between Gram-positive and Gram-negative bacteria. The options provided are related to types of staining.

2. **Definition of Gram Staining**: Gram staining is a differential staining technique that helps to classify bacteria into two groups based on the composition of their cell walls.

3. **Cell Wall Composition**:
- **Gram-positive Bacteria**: These bacteria have a thick peptidoglycan layer in their cell wall. This thick layer retains the crystal violet stain used in the Gram staining process.
- **Gram-negative Bacteria**: These bacteria have a thinner peptidoglycan layer and an outer membrane. They do not retain the crystal violet stain after treatment with alcohol and instead take up the counterstain (safranin), appearing pink.

4. **Differential Staining Process**:
- The process involves applying crystal violet stain, followed by iodine (which acts as a mordant), and then washing with alcohol (which acts as a decolorizer).
- After washing, Gram-positive bacteria retain the crystal violet stain, while Gram-negative bacteria lose it and take up the safranin stain.

5. **Conclusion**: The main difference between Gram-positive and Gram-negative bacteria resides in their cell wall structure, which is highlighted through the differential staining process. Therefore, the correct answer to the question is "differential staining of cell wall."

### Final Answer:
The main difference in Gram (+ve) and Gram (-ve) bacteria resides in their **differential staining of cell wall**.

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