Respiratory pigment found in R.B.C. is known as

Options

A. Haemocyanin
B. Haemoglobin
C. Haemocyanin and haemoglobin
D. None of these.

Answer

**Step-by-Step Solution:**

1. **Identify the Question**: The question asks for the name of the respiratory pigment found in red blood cells (RBCs).

2. **Understand the Function of RBCs**: Red blood cells, also known as erythrocytes, are responsible for transporting gases such as oxygen and carbon dioxide in the body.

3. **Identify the Respiratory Pigment**: The primary respiratory pigment in RBCs is hemoglobin.

4. **Describe Hemoglobin**: Hemoglobin is a quaternary protein composed of four polypeptide chains—two alpha and two beta chains. It contains an iron atom, which is crucial for its function.

5. **Explain the Role of Hemoglobin**: Hemoglobin binds to oxygen in the lungs and carries it to tissues throughout the body. It also helps in transporting carbon dioxide from the tissues back to the lungs.

6. **Differentiate from Other Respiratory Pigments**: While hemoglobin is found in RBCs, other respiratory pigments like hemocyanin are found in some invertebrates (e.g., molluscs) and are present in the plasma rather than in RBCs.

7. **Conclude the Answer**: Therefore, the respiratory pigment found in RBCs is hemoglobin.

**Final Answer**: Hemoglobin

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