Which of the following is NOT found in all bac- terial cells?

Options

A. cell membrane
B. nucleoid
C. ribosomes
D. capsule

Answer

To determine which of the following is NOT found in all bacterial cells, we need to analyze each option provided:

1. **Cell Membrane**:
- All bacterial cells possess a cell membrane. This membrane is essential for maintaining the integrity of the cell and regulating the movement of substances in and out of the cell. Therefore, this option is found in all bacterial cells.

2. **Nucleoid**:
- Bacterial cells do not have a true nucleus; instead, they have a nucleoid region where their genetic material (DNA) is located. This structure is present in all bacterial cells. Thus, this option is also found in all bacterial cells.

3. **Ribosomes**:
- Bacterial cells contain ribosomes, specifically 70S ribosomes, which are necessary for protein synthesis. This component is present in all bacterial cells, making this option also found in all bacterial cells.

4. **Capsule**:
- The capsule is a protective layer that is found in some bacteria but not in all. It is composed of hydrated polysaccharides and is associated with pathogenic bacteria, providing them with an advantage in evading the host's immune system. Therefore, this option is NOT found in all bacterial cells.

Based on the analysis above, the answer to the question is:

**Capsule** (Option D) is NOT found in all bacterial cells.

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