GED Science TestLife ScienceEasy
A medical student is learning about the human immune system. They are taught that a specific type of white blood cell is primarily responsible for producing antibodies, which are crucial for neutralizing extracellular pathogens and toxins. Which of the following cells fits this description?
- AMacrophage
- BT-lymphocyte
- CB-lymphocyte
- DNeutrophil
Show answer & explanationAnswer & explanation
Correct answer: C. B-lymphocyte
B-lymphocytes (B cells) are the immune cells that, upon activation, differentiate into plasma cells that produce and secrete large quantities of antibodies. Antibodies are essential for humoral immunity, targeting pathogens outside of cells.
Why the other options are wrong
- A. Macrophages are phagocytic cells that engulf pathogens and cellular debris, and present antigens, but do not produce antibodies.
- B. T-lymphocytes are involved in cell-mediated immunity (e.g., killing infected cells or regulating immune responses), but do not produce antibodies.
- D. Neutrophils are phagocytic cells involved in the innate immune response, primarily targeting bacteria and fungi, but do not produce antibodies.
B-lymphocyte (B cell)
A type of white blood cell (lymphocyte) that plays a central role in humoral immunity by producing antibodies when activated, targeting extracellular pathogens and toxins.
- Develop in bone marrow.
- Surface receptors (BCRs) bind specific antigens.
- Differentiate into plasma cells to secrete antibodies and memory B cells for future immunity.
Memory trick: B-cells Battle Bad Bugs with Antibodies.