The immune system's specific response and nonspecific response are two different ways in which the body defends itself against pathogens (disease-causing microorganisms).The nonspecific response is the first line of defense against invading pathogens. It includes physical and chemical barriers such as the skin, mucous membranes, stomach acid, and enzymes in tears and saliva. It also involves the activity of white blood cells such as neutrophils and macrophages, which can recognize and engulf foreign particles in the body.On the other hand, the specific response is the second line of defense and is a more complex mechanism. It involves the activation of B and T lymphocytes, which are specific to certain pathogens. These lymphocytes can recognize and bind to a pathogen's unique molecular markers (antigens) and produce antibodies or killer T cells, which attack and destroy the pathogen. The specific response also generates 'memory cells' which retain the pathogen's antigens, allowing for a faster and stronger response if the same pathogen enters the body again.In summary, the nonspecific response is a general defense mechanism that provides an immediate response to any pathogen, while the specific response is a targeted defense mechanism that is specific to certain pathogens and provides a more long-lasting immunity.