Question 27 from UPSC CSE 2022 - Basic Science

Question

Which one of the following statements best describes the role of B cells and T cells in the human body?

Accepted Answer

Correct Option: D. They protect the body from the diseases caused by pathogens.

Strategy: - Identify key terms: B cells and T cells are central to immunology and pathogen immunity.
- Eliminate options relating to pain, inflammation, or environmental allergens, as these are not primary functions of lymphocytes.
- Recognize that the core role of lymphocytes is defense against pathogens, making the option concerning immunity to pathogens the best fit.

Key Info: B cells (B lymphocytes) and T cells (T lymphocytes) are critical white blood cells involved in the adaptive (acquired) immune response.

### B Cells
-   Mature in bone marrow.
-   Responsible for humoral immunity by producing antibodies that target specific pathogens (e.g., bacteria, viruses) in blood and lymph.
-   Upon activation, differentiate into plasma cells to secrete antibodies.

### T Cells
-   Mature in the thymus.
-   Primarily responsible for cell-mediated immunity.
-   Recognize and destroy infected or abnormal cells, activate other immune cells, and regulate immune responses.
-   Types include helper T cells (CD4+), cytotoxic T cells (CD8+), and regulatory T cells.

### Role in Immunity
Both B and T cells are essential for identifying and neutralizing disease-causing microorganisms (pathogens).

They do not act as analgesics, anti-inflammatories, or immunosuppressants. Immune responses to environmental allergens involve different mechanisms (e.g., IgE production, mast cell activation), and pain and inflammation are mediated by other cell types and signaling molecules. Immunosuppressants dampen immune responses, whereas B and T cells enhance it against foreign antigens. Their fundamental role is protecting the body from diseases caused by pathogens.

Answer

Option A: They protect the body from environmental allergens.

Answer

Option B: They alleviate the body's pain and inflammation.

Answer

Option C: They act as immunosuppressants in the body.