The diameter of RBC is

Options

A. `10.3 mu m`
B. `9.2 mu m `
C. `7.2 mu m `
D. `8.1 mu m`.

Answer

**Step-by-Step Solution:**

1. **Understanding the Question**: The question asks for the diameter of red blood cells (RBCs), which are also known as erythrocytes.

2. **Function of RBCs**: RBCs are crucial for transporting oxygen from the lungs to the body's tissues and facilitating the removal of carbon dioxide from the tissues back to the lungs.

3. **Composition of Blood**: RBCs make up about 40 to 45 percent of the total blood volume, which also includes white blood cells (WBCs) and platelets.

4. **Characteristics of Mature RBCs**: In humans, mature RBCs are described as flexible, oval, biconcave in shape, and they lack a nucleus (they are enucleated).

5. **Finding the Diameter**: The diameter of mature human RBCs is specifically noted to be 7.2 micrometers.

6. **Evaluating the Options**: The options provided are:
- 10.3 micrometers
- 9.2 micrometers
- 7.2 micrometers (this is the correct answer)
- 8.1 micrometers

7. **Conclusion**: Based on the information, the correct answer is 7.2 micrometers.

**Final Answer**: The diameter of RBC is 7.2 micrometers.

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