Biology · PYQ NEET UG 2019(2)

Humans have acquired immune system that produces antibodies to neutralize pathogens. Still innate immune system is present at the time of birth because it

1. A
   provides passive immunity
2. B
   is very specific and uses different macrophages.
3. C
   produces memory cells for mounting fast secondary response.
4. D
   has natural killer cells which can phagocytose and destroy microbes