Infections occuring in AIDS due to immunodeficiency.

Answer

### Step-by-Step Solution:

1. **Understanding AIDS**:
- AIDS stands for Acquired Immunodeficiency Syndrome. It is a condition that results from the infection with the Human Immunodeficiency Virus (HIV).

2. **Role of HIV**:
- HIV is a retrovirus that contains RNA as its genetic material. When it enters the human body, it targets and infects the immune system, specifically the helper T cells (TH cells).

3. **Impact on Immune System**:
- The virus takes over the genetic machinery of the host's cells, leading to the production of new virus particles. This process ultimately weakens the immune response of the individual.

4. **Opportunistic Infections**:
- Due to the compromised immune system, individuals with AIDS become susceptible to infections that would normally be controlled by a healthy immune system. These infections are termed "opportunistic infections."

5. **Types of Opportunistic Infections**:
- Common opportunistic infections associated with AIDS include:
- Pneumonia (especially Pneumocystis pneumonia)
- Tuberculosis
- Candidiasis (thrush)
- Infections caused by mycobacterium, viruses, and protozoans.

6. **Conclusion**:
- In summary, the infections occurring in AIDS due to immunodeficiency are known as opportunistic infections, which can significantly affect the health of the individual.