**Plasma membrane in Eubacteria**

The correct answer is option 'A' - Plasma membrane. The plasma membrane in eubacteria resembles the plasma membrane found in eukaryotic cells. Let's understand this in detail:

**Eubacteria**
Eubacteria, also known as true bacteria, are prokaryotic organisms that belong to the kingdom Bacteria. They are single-celled organisms that lack a true nucleus and other membrane-bound organelles. Eubacteria have a simple cellular structure and contain various cellular components.

**Cellular Components of Eubacteria**
Eubacteria possess several cellular components that play crucial roles in their structure and function. Some of these components include:
- Plasma membrane
- Nucleoid
- Ribosomes
- Cell wall
- Cytoplasm
- Flagella
- Pili

**Plasma Membrane**
The plasma membrane, also known as the cell membrane, is a thin, flexible, and semi-permeable structure that surrounds the cytoplasm of a cell. It acts as a barrier between the intracellular and extracellular environments, controlling the passage of molecules in and out of the cell.

**Resemblance to Eukaryotic Cells**
The plasma membrane in eubacteria resembles the plasma membrane found in eukaryotic cells in several ways:

1. **Phospholipid Bilayer Structure**: Both eubacterial and eukaryotic plasma membranes are composed of a phospholipid bilayer. The phospholipids have hydrophilic (water-loving) heads and hydrophobic (water-fearing) tails, arranging themselves in a double layer.

2. **Selective Permeability**: The plasma membrane in eubacteria, like eukaryotic cells, is selectively permeable. It regulates the movement of substances into and out of the cell, allowing the passage of certain molecules while restricting the entry of others.

3. **Protein Components**: Both types of plasma membranes contain proteins that are involved in various cellular processes. These proteins can function as transporters, receptors, enzymes, or structural components.

4. **Fluid Mosaic Model**: The plasma membrane in eubacteria, similar to eukaryotic cells, follows the fluid mosaic model. This model describes the arrangement of phospholipids, proteins, and other molecules in the membrane, forming a dynamic and fluid structure.

Overall, the plasma membrane in eubacteria resembles the plasma membrane in eukaryotic cells in terms of structure, composition, and function. However, it is important to note that there are also significant differences between the plasma membranes of eubacteria and eukaryotic cells, such as the absence of cholesterol in eubacterial membranes.

In conclusion, the plasma membrane in eubacteria is a cellular component that resembles the plasma membrane found in eukaryotic cells. It plays a vital role in maintaining cell integrity, regulating the passage of molecules, and facilitating various cellular processes.