Which of the following structures or materials is incorrectly matched with a tissue?

Options

A. Haversian system-bone
B. Fibroblasts—skeletal muscle
C. Chondrin-cartilage
D. Basement membrane-epithelium

Explanation

To solve the question of which structure or material is incorrectly matched with a tissue, we will analyze each option provided in the question.

### Step-by-Step Solution:

1. **Understand the Options**:
- The options given are:
- Haversian system, bone
- Fibroblast in skeletal muscle
- Cartilage (contouring)
- Basement membrane in epithelium

2. **Analyze Each Option**:
- **Haversian System and Bone**:
- The Haversian system (also known as osteon) is indeed a structural unit of compact bone tissue. It is responsible for the strength and protection of bones. This option is correctly matched.

- **Fibroblast in Skeletal Muscle**:
- Fibroblasts are a type of cell that synthesizes extracellular matrix and collagen. They are primarily associated with connective tissues, not skeletal muscle. This option is incorrectly matched.

- **Cartilage (Contouring)**:
- The term "contouring" is not standard, but if we consider cartilage itself, it is a flexible connective tissue that provides support and elasticity. This option seems to be correctly matched if we interpret it as referring to the properties of cartilage.

- **Basement Membrane in Epithelium**:
- The basement membrane (or basal lamina) is indeed a layer of protein that supports epithelial cells and separates them from underlying connective tissue. This option is also correctly matched.

3. **Identify the Incorrect Match**:
- From the analysis, the only incorrect match is **Fibroblast in Skeletal Muscle**. Fibroblasts are not typically found in skeletal muscle tissue; they are more associated with connective tissues.

### Conclusion:
The structure or material incorrectly matched with a tissue is **Fibroblast in Skeletal Muscle**.

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