A Gram positive bacteria -retains a ______ colour

Explanation

**Step-by-Step Solution:**

1. **Understanding Gram Staining**: The Gram staining procedure is a method used to classify bacteria into two groups: Gram-positive and Gram-negative. This classification is based on the characteristics of their cell walls.

2. **Cell Wall Composition**: Gram-positive bacteria have a thick peptidoglycan layer in their cell wall. This thick layer is crucial because it retains the dye used in the Gram staining process.

3. **Staining Process**: During the Gram staining procedure, a crystal violet dye is applied to the bacterial cells. Gram-positive bacteria absorb and retain this dye due to their thick peptidoglycan layer.

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