Select the correct statement

Options

A. Rheumatoid arthritis is an example auto immune disease.
B. Body secretions lack antibodies
C. Genetic material of HIV is ds DNA
D. Spleen is a primary lymphoid organ

Answer

To solve the question of selecting the correct statement regarding various biological concepts, let's analyze each option step by step.

### Step 1: Evaluate Option 1
**Statement:** Rheumatoid Arthritis is an example of Autoimmune Disease.

- **Analysis:** Rheumatoid Arthritis (RA) is indeed classified as an autoimmune disease. In autoimmune diseases, the immune system mistakenly attacks the body's own healthy cells. In the case of RA, it primarily affects the joints, causing inflammation and pain. Therefore, this statement is **correct**.

### Step 2: Evaluate Option 2
**Statement:** Body secretions lack antibodies.

- **Analysis:** This statement is incorrect. Body secretions such as breast milk, gastric juice, and mucus do contain antibodies. Antibodies play a crucial role in the immune response by binding to pathogens and marking them for destruction. Thus, this statement is **incorrect**.

### Step 3: Evaluate Option 3
**Statement:** The genetic material of HIV is double-stranded DNA.

- **Analysis:** This statement is also incorrect. HIV (Human Immunodeficiency Virus) is a retrovirus that contains single-stranded RNA as its genetic material, not double-stranded DNA. Therefore, this statement is **incorrect**.

### Step 4: Evaluate Option 4
**Statement:** Spleen is a primary lymphoid organ.

- **Analysis:** This statement is incorrect as well. The primary lymphoid organs are the bone marrow and thymus, where lymphocytes are produced. The spleen is classified as a secondary lymphoid organ, where the maturation and activation of lymphocytes occur. Thus, this statement is **incorrect**.

### Conclusion
After evaluating all the options, the only correct statement is **Option 1: Rheumatoid Arthritis is an example of Autoimmune Disease**.

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