The correct arrangement of blood cell is

Options

A. In terms of quantity: erythrocytes `gt` lymphocytes `gt` monocytes `gt` thrombocytes
B. In terms of life span: thrombocytes `gt` erythrocytes `gt` monocytes `gt` lymphocytes
C. In terms of size : monocytes `gt` lymphocytes `gt` erythrocytes `gt` thrombocytes
D. In terms of motility : erythrocytes `gt` thrombocytes `gt` lymphocytes `gt` monocytes

Answer

To solve the question regarding the correct arrangement of blood cells, we need to analyze the options based on different criteria such as quantity, lifespan, size, and mortality.

### Step-by-Step Solution:

1. **Understanding Blood Cells**:
- Blood is composed of various types of cells, primarily erythrocytes (red blood cells), leukocytes (white blood cells), and thrombocytes (platelets).
- The main types of leukocytes include lymphocytes, monocytes, neutrophils, eosinophils, and basophils.

2. **Option Analysis**:
- **Option 1 (Quantity)**:
- Erythrocytes are the most abundant, making up about 70% of blood cells (20-30 trillion).
- Lymphocytes make up about 20-40% of white blood cells (1000-4800 per microliter).
- Monocytes account for about 2-8% of white blood cells.
- Thrombocytes (platelets) range from 150,000 to 450,000 per microliter.
- This option is incorrect as it does not follow the correct order based on quantity.

- **Option 2 (Lifespan)**:
- Thrombocytes have a lifespan of about 10 days.
- Erythrocytes live for approximately 120 days.
- Monocytes circulate for about 71 hours.
- Lymphocytes can live from a week to several months.
- This option is also incorrect as it does not follow the correct order based on lifespan.

- **Option 3 (Size)**:
- Monocytes are the largest cells among the blood cells.
- Lymphocytes are smaller than monocytes but larger than erythrocytes.
- Erythrocytes are smaller than lymphocytes.
- Thrombocytes (platelets) are the smallest.
- This option is correct as it accurately arranges cells from largest to smallest: Monocytes > Lymphocytes > Erythrocytes > Thrombocytes.

- **Option 4 (Mortality)**:
- This option is also incorrect as it does not follow the correct order based on mortality.

3. **Conclusion**:
- The correct arrangement of blood cells based on size is: **Monocytes > Lymphocytes > Erythrocytes > Thrombocytes**. Therefore, the correct answer is **Option 3**.