Which of the following WBC has the largest nucleus?

Options

A. Lymphocyte
B. Monocyte
C. Eosinophils
D. Basophils

Answer

To determine which white blood cell (WBC) has the largest nucleus, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Types of WBCs**: White blood cells are classified into two main categories: agranulocytes and granulocytes. Agranulocytes include lymphocytes and monocytes, while granulocytes include eosinophils, basophils, and neutrophils.

2. **Examine Agranulocytes**:
- **Monocytes**: These are larger cells but have a round or spherical nucleus. The nucleus is not particularly large in comparison to other WBCs.
- **Lymphocytes**: These cells are smaller than monocytes but have a significantly larger nucleus. The nucleus is typically round or slightly indented.

3. **Examine Granulocytes**:
- **Eosinophils (Acidophils)**: These have a bilobed nucleus, which means it has two lobes.
- **Basophils**: Their nucleus is irregular and often resembles an "S" shape.
- **Neutrophils**: These have a multi-lobed nucleus, which can have anywhere from 2 to 7 lobes.

4. **Compare Nucleus Sizes**: When we compare the nuclei of all these WBCs:
- The nucleus of lymphocytes is larger than that of monocytes.
- Among granulocytes, eosinophils, basophils, and neutrophils have smaller nuclei compared to lymphocytes.

5. **Conclusion**: After comparing the sizes of the nuclei, we conclude that the lymphocyte has the largest nucleus among the options provided.

### Final Answer:
The white blood cell with the largest nucleus is the **lymphocyte**.

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