Which of the following is a suitable example of innate immunity ?

Options

A. PMN-neutrophils
B. T- lymphocytes
C. B-lymphocytes
D. TH cells

Answer

### Step-by-Step Solution:

1. **Understanding Innate Immunity**:
- Innate immunity is the type of immunity that is present from birth. It is inherited from parents and is not acquired through exposure to pathogens.

2. **Identifying the Characteristics of Innate Immunity**:
- Innate immunity includes various barriers such as physical barriers (skin), physiological barriers (temperature, pH), cellular barriers (white blood cells), and cytokine barriers (chemical signals).

3. **Distinguishing Between Innate and Acquired Immunity**:
- Acquired immunity is developed after exposure to pathogens and involves specific immune responses, primarily mediated by T cells and B cells.

4. **Analyzing the Options**:
- Option 1: PMN neutrophils - These are a type of white blood cell involved in the innate immune response.
- Option 2: T lymphocytes - These are part of the acquired immune system.
- Option 3: B lymphocytes - These are also part of the acquired immune system.
- Option 4: TH cells (T helper cells) - These are involved in the acquired immune response.

5. **Selecting the Correct Answer**:
- Since PMN neutrophils are white blood cells that play a crucial role in the innate immune response, they are the most suitable example of innate immunity.

### Final Answer:
The suitable example of innate immunity is **Option 1: PMN neutrophils**.

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