Answer: B cells (plasma cells).
- A T cells, which instead attack infected cells directly
- B Macrophages, which engulf and digest pathogens
- C B cells (plasma cells)
- D Neutrophils, which respond first to acute infection
Correct answer: C. B cells (plasma cells)
Explanation: B cells differentiate into plasma cells that produce antibodies (immunoglobulins). Each plasma cell produces one specific antibody.
An antibody is Y-shaped, with two identical antigen-binding sites at the tips of the variable regions - each shaped to recognise one specific antigen - while the constant (Fc) region at the base is recognised by immune cells to trigger further responses.
Concept context
Innate and adaptive immunity, B cells, T cells, antibodies, vaccines, and immune disorders. Critical for NEET.