Number of erythrocytes per `m m^(3)` of human blood is

Options

A. 4 million
B. 5 million
C. 6 million
D. 0.5 million

Answer

To determine the number of erythrocytes (red blood cells) per cubic millimeter (mm³) of human blood, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Erythrocytes**:
- Erythrocytes, or red blood cells (RBCs), are biconcave disc-shaped cells that lack a nucleus in humans. They contain hemoglobin, which is responsible for the red color of blood and plays a crucial role in transporting oxygen and carbon dioxide.

2. **RBC Count Variation**:
- The number of erythrocytes in human blood can vary based on factors such as age and sex.

3. **Normal Range for Women**:
- The typical range of erythrocytes for women is approximately 4.2 to 5 million per microliter of blood.

4. **Normal Range for Men**:
- For men, the range is slightly higher, approximately 4.6 to 6.0 million per microliter of blood.

5. **Average Erythrocyte Count**:
- To find a general average for adults, we can consider the ranges provided. The average number of erythrocytes can be approximated to about 4.5 to 5 million per mm³ of blood.

6. **Final Answer**:
- Therefore, the number of erythrocytes per mm³ of human blood is typically around **5 million**.

### Summary:
The number of erythrocytes per mm³ of human blood is approximately **5 million**.

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