Components of cell envelope in prokaryotic cells are
I.Capsule II. Slime layer III. Cell wall IV. Cell membrane

Options

A. I or II, III only
B. I, II &III only
C. IV only
D. I or II,III, IV

Answer

To solve the question regarding the components of the cell envelope in prokaryotic cells, we will analyze each of the provided options step by step.

### Step-by-Step Solution:

1. **Identify the Components**:
The question lists four components:
- I. Capsule
- II. Slime layer
- III. Cell wall
- IV. Cell membrane

2. **Evaluate Each Component**:
- **Capsule**:
- The capsule is a well-defined layer that is tightly attached to the bacterial cell. It plays a significant role in protecting the bacteria from phagocytosis and helps in adhesion.
- **Conclusion**: The capsule is a component of the cell envelope.

- **Slime Layer**:
- The slime layer is a less organized and loosely associated layer compared to the capsule. It also aids in adhesion and can protect the bacteria from desiccation.
- **Conclusion**: The slime layer is also a component of the cell envelope.

- **Cell Wall**:
- The cell wall provides structural support and protection to the cell. In prokaryotic cells, it is typically composed of peptidoglycan (not cellulose and chitin, which are found in plant and fungal cells, respectively).
- **Conclusion**: The cell wall is a crucial component of the cell envelope.

- **Cell Membrane**:
- The cell membrane (or plasma membrane) is present in all cells, including prokaryotes. It regulates the movement of substances in and out of the cell.
- **Conclusion**: The cell membrane is also a component of the cell envelope.

3. **Summarize the Findings**:
All four components listed (capsule, slime layer, cell wall, and cell membrane) are indeed part of the cell envelope in prokaryotic cells.

4. **Select the Correct Answer**:
Since all four components are correct, the answer is option 4: "1st, 2nd, 3rd, and 4th."

### Final Answer:
The components of the cell envelope in prokaryotic cells are:
- I. Capsule
- II. Slime layer
- III. Cell wall
- IV. Cell membrane

Thus, the correct answer is option 4: "1st, 2nd, 3rd, and 4th."

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