Human Health and Diseases Question 53
53. Humans have acquired immune system that produces antibodies to neutralise pathogens. Still innate immune system is present at the time of birth because it
(a) provides passive immunity.
(b) is very specific and uses different macrophages.
(c) produces memory cells for mounting fast secondary response.
(d) has natural killer cells which can phagocytose and destroy microbes.
Show Answer
Answer : d
Hints & Solutions
(d) Innate immunity is non-specific and is accomplished by providing different types of barriers to the entry of foreign agent or any pathogen into our body. Through this immunity, the human body protects itself against foreign material that is percieved to be harmful. Natural killer cells are a type of lymphocytes which will produce proteins called perforins that create pores on plasma membrane of tumour cells and virally infected cells through which ECF enters and kill the cells. Passive immunity is specific and is a branch of humoral immunity. Innate immunity does not produce memory cells hence, no secondary immune response is seen.
