- A Mainly physical engulfment of the bacterium by the cell's plasma membrane folding largely around it under typical conditions
- B Oxidative burst (NADPH oxidase producing superoxide), MPO (hypochlorous acid from H2O2 + Cl-), defensins, and elastase
- C Mainly degranulation of preformed granules releasing their antimicrobial contents alone each time according to standard textbooks
- D Mainly T cell activation by helper cells, with little role for neutrophils themselves in the process in general practice
Correct answer: B. Oxidative burst (NADPH oxidase producing superoxide), MPO (hypochlorous acid from H2O2 + Cl-), defensins, and elastase
Explanation: Neutrophil killing: phagocytosis + NADPH oxidase oxidative burst (O2- → H2O2) + myeloperoxidase (H2O2 + Cl- → HOCl) + defensins (membrane disruption) + proteases (elastase, cathepsins).
Concept context
Innate and adaptive immunity, B cells, T cells, antibodies, vaccines, and immune disorders. Critical for NEET.