Extension and recoiling of elastic connective tissue is due to  

Options

A. collagen fibres
B. yellow elastin fibres
C. tendons
D. actin

Answer

**Step-by-Step Solution:**

1. **Understanding Elastic Connective Tissue:**
- Elastic connective tissue is a type of connective tissue that provides elasticity and flexibility to various structures in the body. It is primarily composed of elastic fibers.

2. **Identifying the Components:**
- The main components of elastic connective tissue include:
- **Elastic fibers (yellow elastic fibers):** These fibers are responsible for the elasticity of the tissue.
- **Collagen fibers:** These provide strength but do not contribute to elasticity.
- **Tendons:** These connect muscles to bones and are not elastic connective tissue.
- **Actin:** This is a protein found in muscle cells, not in connective tissue.

3. **Analyzing the Options:**
- The question provides four options:
1. Collagen fibers
2. Yellow elastin fibers
3. Tendons
4. Actin
- Among these, we need to identify which component is responsible for the extension and recoiling of elastic connective tissue.

4. **Eliminating Incorrect Options:**
- **Collagen fibers:** These provide strength and toughness, not elasticity. Therefore, this option can be eliminated.
- **Tendons:** Tendons connect muscles to bones and do not have elastic properties, so this option is also eliminated.
- **Actin:** This protein is involved in muscle contraction and is not part of elastic connective tissue, thus it can be eliminated as well.

5. **Identifying the Correct Answer:**
- The only option left is **yellow elastin fibers**, which are specifically responsible for the elasticity and the ability to stretch and recoil in elastic connective tissue.

6. **Conclusion:**
- Therefore, the extension and recoiling of elastic connective tissue is due to **yellow elastin fibers**.

**Final Answer: Yellow elastin fibers.**

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