Q. Which one of the following acts as a physiological barrier preventing the entry of microorganisms in human body?
(a) Epithelium of urogenital tract
(b) Tears
(c) Monocytes
(d) Skin
Solution : Correct option : B Physiological barrier in an innate immune system is a barrier that prevents the entry of microorganisms in human body. These include tears, saliva, acidic pH in stomach, bile in intestine. Physical barrier in an innate immune system is a barrier that prevents the entry of microorganisms physically. It includes skin, mucous membrane.