Which of the following tissues has closely linked cells and one free surface?

Options

A. Epithelial
B. Connective
C. Nervous
D. Muscle

Explanation

To answer the question, "Which of the following tissues has closely linked cells and one free surface?", we can follow these steps:

### Step-by-Step Solution

1. **Identify the Types of Tissues**: The question provides four options: epithelial tissue, connective tissue, nervous tissue, and muscle tissue. We need to analyze each type to see which fits the criteria of having closely linked cells and one free surface.

2. **Understand Epithelial Tissue**: Epithelial tissue is characterized by closely packed cells with minimal extracellular matrix. This tissue forms protective coverings and linings for both external and internal organs.

3. **Examine the Structure of Epithelial Tissue**: Epithelial tissues have one free surface (the apical surface) that is exposed to either the external environment or the internal body cavity. The opposite side of the epithelial tissue is anchored to the underlying connective tissue by a basement membrane.

4. **Compare with Other Tissues**:
- **Connective Tissue**: This type of tissue is characterized by a significant amount of extracellular matrix and does not have closely linked cells. It serves to support and connect different tissues.
- **Nervous Tissue**: Composed mainly of neurons and supporting cells, nervous tissue does not have the structure of closely linked cells with a free surface.
- **Muscle Tissue**: Muscle tissue is made up of muscle fibers and is primarily involved in movement, but it does not have the characteristic of closely linked cells with a free surface.

5. **Conclusion**: Based on the analysis, epithelial tissue is the only type that has closely linked cells and one free surface. Therefore, the correct answer to the question is **epithelial tissue**.

### Final Answer
**Epithelial tissue** is the tissue that has closely linked cells and one free surface.

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