Answer and Explanation:
1) Second line of Defense ---------> includes cells and processes that help remove or neutralize organisms that have penetrated mechanical barriers.
Second line of Defense uses cells such as phagocytic leukocytes and antimicrobial proteins or uses a procedures like inflammatory responses and fever in order to combat with the pathogens which crosses the first line of Defense
2) First line of Defense ---------> includes mechanical barriers that prevent microorganisms from entering the body.
Skin mucous membranes and other secretions of the skin works as the first line of Defense which provides a barrier that prevents the entry of pathogens into the body in first place.
3) Third line of Defense ---------> is a complex defense system that recognizes and reacts to specific organism.
If pathogens somehow manage to cross the first and second line of Defense, it's then encounter by the third line of Defense which is a specialized systems used to kill these pathogens altogether. This includes Lymphocytes, antibodies and memory cells which helps in permanently killing the foreign pathogen.
