Ratio WBC `//` RBC in human blood `:-`

Options

A. `1:100`
B. `1:200`
C. `500:1`
D. `1:600`

Answer

To find the ratio of white blood cells (WBC) to red blood cells (RBC) in human blood, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Components**:
- WBC (White Blood Cells) are also known as leukocytes and are responsible for immune responses.
- RBC (Red Blood Cells) are also known as erythrocytes and are responsible for transporting oxygen in the blood.

2. **Know the Normal Ranges**:
- The normal range for RBCs in a healthy human is approximately **4.2 million to 6.1 million per microliter** of blood.
- The normal range for WBCs is approximately **4,500 to 11,000 per microliter** of blood.

3. **Calculate the Average Values**:
- For RBCs, we can take an average of the normal range:
\[ \text{Average RBC} = \frac{4.2 \text{ million} + 6.1 \text{ million}}{2} = 5.15 \text{ million} \]
- For WBCs, we can also take an average of the normal range:
\[ \text{Average WBC} = \frac{4500 + 11000}{2} = 7850 \]

4. **Convert to the Same Units**:
- To compare WBCs and RBCs, we can express them in the same units. Since 1 million = 1,000,000, we convert the average RBC count:
\[ \text{Average RBC} = 5.15 \text{ million} = 5,150,000 \]

5. **Calculate the Ratio**:
- Now we can find the ratio of WBCs to RBCs:
\[ \text{Ratio} = \frac{\text{Average WBC}}{\text{Average RBC}} = \frac{7850}{5,150,000} \]
- Simplifying this gives:
\[ \text{Ratio} \approx 1 : 600 \]

6. **Conclusion**:
- Therefore, the ratio of WBC to RBC in human blood is approximately **1:600**.

### Final Answer:
The ratio of WBC to RBC in human blood is **1:600**.

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