GED Science TestLife ScienceMedium
A medical researcher is studying a group of individuals who have a genetic predisposition to a certain autoimmune disease. The disease is characterized by the immune system mistakenly attacking healthy cells and tissues in the body. Which of the following components of the immune system is primarily responsible for differentiating between 'self' (healthy body cells) and 'non-self' (pathogens or abnormal cells) to prevent such autoimmune responses?
- ANatural Killer cells
- BB lymphocytes
- CMacrophages
- DT lymphocytes
Show answer & explanationAnswer & explanation
Correct answer: D. T lymphocytes
T lymphocytes, particularly helper T cells and cytotoxic T cells, are crucial for cell-mediated immunity and play a primary role in recognizing and distinguishing between self and non-self antigens, preventing autoimmune attacks.
Why the other options are wrong
- A. Natural Killer cells primarily target and destroy infected or cancerous cells but do not have the same sophisticated self/non-self recognition mechanisms as T cells.
- B. B lymphocytes primarily produce antibodies, which target pathogens in the bloodstream, but are not the main cells for self/non-self recognition.
- C. Macrophages are phagocytic cells that engulf and digest pathogens and cellular debris, and present antigens, but they are not the primary cells for self/non-self discrimination.
T Lymphocyte Function
T lymphocytes (T cells) are a type of white blood cell that plays a central role in cell-mediated immunity, including recognizing and differentiating between self and non-self cells to protect against pathogens and prevent autoimmunity.
- Mature in the thymus.
- Recognize specific antigens presented by MHC molecules.
- Crucial for both adaptive immunity and preventing autoimmune diseases.
Memory trick: Immunity's T-team: Targeting Trouble, Trusting 'Self'.