Choose the odd pair

Options

A. Areolar connective tissue - Collagen
B. Epithelium - Keratin
C. Muscle fibre - Actin
D. Neuron - Melanin.

Answer

To solve the question of choosing the odd pair from the given options, we will analyze each pair based on their biological relationships.

### Step-by-Step Solution:

1. **Analyze the first pair: Areolar connective tissue and collagen**
- Areolar connective tissue is a type of connective tissue that contains collagen fibers among other components. Therefore, this pair is related.

2. **Analyze the second pair: Epithelium and keratin**
- Epithelium is a type of tissue that can contain keratin, especially in stratified squamous epithelium. Keratin is a protein produced by keratinocytes in the epithelial layer. Thus, this pair is also related.

3. **Analyze the third pair: Muscle fiber and actin**
- Muscle fibers contain proteins such as actin and myosin, which are essential for muscle contraction. Hence, this pair is related as well.

4. **Analyze the fourth pair: Neuron and melanin**
- Neurons are the structural and functional units of the nervous system, while melanin is a pigment responsible for skin and hair color. There is no direct relationship between neurons and melanin. Therefore, this pair is not related.

5. **Conclusion: Identify the odd pair**
- Based on the analysis, the odd pair is **neuron and melanin** since they belong to different biological systems and do not have a direct connection.

### Final Answer:
The odd pair is **neuron and melanin**.

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