1) Any organism that causes disease is classified as a(n) pathogen. mechanical vector. antigen. biological vector. 2) Immunity that develops over time due to exposure to various antigens is termed adaptive immunity. innate immunity. coordinated immunity learned immunity. 3) The core of the immune system is made up of intact mucus membranes. intact skin. red blood cells. white blood cells. 4) The first barrier to invasion is antibody production.