Which statement is true for WBC ?

Options

A. Non-nucleated
B. Its deficiency causes cancer
C. Manufactured only in thymus
D. Can squeeze through blood capillaries

Explanation

To determine which statement is true for white blood cells (WBCs), let's analyze the provided options step by step.

### Step-by-Step Solution:

1. **Understanding WBCs**:
- White blood cells, or leukocytes, are a crucial part of the immune system. They help protect the body against infections and foreign invaders.

2. **Characteristics of WBCs**:
- WBCs are **nucleated** cells, meaning they contain a nucleus. This is an important characteristic that distinguishes them from red blood cells, which are non-nucleated.
- They are **colorless**, which is why they are referred to as white blood cells.

3. **Formation of WBCs**:
- WBCs are produced in two main locations: the **bone marrow** and the **thymus**. Granulocytes (a type of WBC) are primarily formed in the bone marrow, while agranulocytes (another type) can be formed in both the bone marrow and thymus.

4. **WBCs and Cancer**:
- An increase in WBC count can lead to a condition known as **leukemia**, which is a type of blood cancer. This means that a deficiency in WBCs does not cause cancer; rather, an excess does.

5. **Diapedesis**:
- WBCs have the ability to **squeeze through blood capillaries**, a process known as **diapedesis**. This allows them to move out of the bloodstream and into tissues where they are needed to fight infections.

6. **Evaluating the Statements**:
- **Non-nucleated**: False. WBCs are nucleated.
- **Its deficiency causes cancer**: False. An excess of WBCs can lead to leukemia, not a deficiency.
- **Manufactured only in the thymus**: False. WBCs are manufactured in both the bone marrow and thymus.
- **Can squeeze through the blood capillaries**: True. This is a characteristic of WBCs due to diapedesis.

### Conclusion:
The true statement for WBCs is that they **can squeeze through the blood capillaries**.