Hydroxyapatite constitutes

Options

A. Bone
B. Cartilage
C. Teeth
D. Nails

Answer

**Step-by-Step Solution:**

1. **Understanding Hydroxyapatite**: Hydroxyapatite is a mineral form of calcium apatite, primarily composed of calcium and phosphate ions. It is a crucial component of various biological structures.

2. **Identifying Structures**: The question asks what hydroxyapatite constitutes. The options provided are bone, cartilage, teeth, and nails.

3. **Analyzing Each Option**:
- **Bone**: Hydroxyapatite is a major component of bone tissue, providing strength and rigidity.
- **Cartilage**: Cartilage primarily consists of collagen and proteoglycans, and does not contain hydroxyapatite.
- **Teeth**: Hydroxyapatite is also a significant component of tooth enamel and dentin, contributing to their hardness.
- **Nails**: Nails are primarily made of keratin, and do not contain hydroxyapatite.

4. **Conclusion**: Based on the analysis, hydroxyapatite constitutes both bone and teeth. Therefore, the correct options are bone and teeth.

**Final Answer**: Hydroxyapatite constitutes bone and teeth.

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