Which one of the following acts as a physiological barrier to the entry of microorganisms in human body?

Step-by-step solution

Physiological barriers to the entry of microorganisms in human body are tears in eyes, saliva in mouth and HCl in stomach. The enzyme lysozyme is found in tears and saliva, and inhibits the synthesis of peptidoglycan present in the cell wall of microorganisms especially eubacteria.