Which of the following is not found in all bacteria?

Explanation

The capsule is a slimy, protective layer that surrounds some bacterial cells. It is composed of polysaccharides or similar materials and helps bacteria evade the host immune system and resist environmental stresses. However, not all bacteria possess capsules; it is a feature found in certain bacterial species but not in all. The capsule of a bacterium is a specific and well-defined structure. The capsule is a protective layer that surrounds the bacterial cell, located outside the cell wall (if present). It is composed of a gel-like substance, primarily consisting of polysaccharides or occasionally polypeptides.