Average life span of human RBC is

Options

A. 120 days
B. 90 days
C. 2-3days
D. 20 days

Answer

**Step-by-Step Solution:**

1. **Understanding Red Blood Cells (RBCs):**
- Red blood cells are a crucial component of blood, primarily responsible for transporting oxygen from the lungs to the rest of the body and returning carbon dioxide from the body back to the lungs.

2. **Components of Blood:**
- Blood consists of several components, including red blood cells (RBCs), white blood cells (WBCs), platelets, and plasma. Plasma is the liquid part of blood, while RBCs, WBCs, and platelets are the solid components.

3. **Structure of RBCs:**
- RBCs are typically round and flat with a dent in the center, which increases their surface area for gas exchange.

4. **Function of Hemoglobin:**
- Hemoglobin is a protein found in RBCs that binds to oxygen and carbon dioxide, facilitating their transport throughout the body.

5. **Lifespan of RBCs:**
- The average lifespan of human red blood cells is approximately 120 days. After this period, they are typically destroyed in the spleen.

6. **Identifying the Correct Answer:**
- Given the options: 120 days, 90 days, 2 to 3 days, and 20 days, the correct answer is 120 days.

**Final Answer:** The average lifespan of human RBCs is 120 days.

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