Transplantation of tissues/organs to save certain patients often fails due to rejection of such tissues/organs by the patient. Which type of immune response is responsible for such rejections?

Options

A. Auto-immune response
B. Humoral immune response
C. Physiological immune response
D. Cell-mediated immune response

Explanation

**Step-by-Step Solution:**

1. **Understanding Transplantation**: Transplantation involves replacing a diseased organ or tissue with a healthy one from the same or another individual. This process is crucial for saving lives but can lead to complications.

2. **Rejection of Transplants**: The body’s immune system can recognize transplanted tissues or organs as foreign. When this happens, the immune system mounts a response against the transplant, leading to rejection.

3. **Role of the Immune System**: The immune system differentiates between self (the body’s own cells) and non-self (foreign cells). This ability is essential for identifying potentially harmful invaders.

4. **Type of Immune Response**: The immune response responsible for the rejection of transplanted tissues or organs is primarily the **cell-mediated immune response**. This response is mediated by T-lymphocytes (T-cells), which play a critical role in identifying and attacking foreign antigens.

5. **Conclusion**: Therefore, the type of immune response responsible for the rejection of transplanted tissues or organs is the **cell-mediated immune response**.

**Final Answer**: The immune response responsible for the rejection of transplanted tissues/organs is the **cell-mediated immune response**.

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