Which of the following statements is correct?

Options

A. Acquired immunity is pathogen specific
B. The exaggerated response of the immune system to certain antigens present in the environment is called Auto-immunity
C. Bone marrow acts as a filter of the blood by trapping blood borne micro-organisms
D. AIDS is caused by a group of viruses called rhinovirus.

Answer

To determine which statement is correct, we will analyze each of the four statements provided in the question.

### Step-by-Step Solution:

1. **Analyze the First Statement:**
- **Statement:** Acquired immunity is pathogen specific.
- **Explanation:** Acquired immunity refers to the immunity that develops after exposure to a specific pathogen. This type of immunity is indeed pathogen-specific, meaning it targets specific antigens associated with particular pathogens.
- **Conclusion:** This statement is correct.

2. **Analyze the Second Statement:**
- **Statement:** The exaggerated response of the immune system to certain antigens present in the environment is called autoimmunity.
- **Explanation:** Autoimmunity occurs when the immune system mistakenly attacks the body's own cells. An exaggerated response to environmental antigens is typically referred to as an allergic reaction, not autoimmunity.
- **Conclusion:** This statement is incorrect.

3. **Analyze the Third Statement:**
- **Statement:** Bone marrow acts as a filter of the blood by trapping microorganisms.
- **Explanation:** Bone marrow is primarily responsible for the production of blood cells, including red blood cells, white blood cells, and platelets. It does not function as a filter for blood; that role is typically associated with organs like the spleen or lymph nodes.
- **Conclusion:** This statement is incorrect.

4. **Analyze the Fourth Statement:**
- **Statement:** AIDS is caused by the group of viruses called rhinovirus.
- **Explanation:** AIDS (Acquired Immunodeficiency Syndrome) is caused by the Human Immunodeficiency Virus (HIV), which is a retrovirus. Rhinoviruses are responsible for the common cold and are not related to AIDS.
- **Conclusion:** This statement is incorrect.

### Final Conclusion:
The only correct statement is that **acquired immunity is pathogen specific.**

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