The colour of human blood is red due to

Options

A. Mayoglobin
B. Haemoglobin
C. Immunoglobin
D. Heptoglobin

Explanation

**Step-by-Step Solution:**

1. **Understanding Blood Color**: Human blood is known for its red color. This characteristic color is primarily due to specific proteins present in the blood.

2. **Identifying the Key Protein**: Among the options provided (myoglobin, hemoglobin, immunoglobin, haptoglobin), we need to identify which protein is responsible for the red color of blood.

3. **Analyzing the Options**:
- **Myoglobin**: This protein is found in muscle tissue and is responsible for storing oxygen, but it is not the main reason for the red color of blood.
- **Hemoglobin**: This is a protein found in red blood cells and is responsible for transporting oxygen from the lungs to the rest of the body. Hemoglobin contains iron, which gives blood its red color.
- **Immunoglobin**: This is related to the immune system and does not contribute to the color of blood.
- **Haptoglobin**: This protein binds free hemoglobin released from red blood cells but does not influence the color of blood.

4. **Conclusion**: The red color of human blood is primarily due to the presence of hemoglobin. Therefore, the correct answer is **B) Hemoglobin**.

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