A non-specific immune response (also called immunity) is antigen-independent while a specific immune response is antigen-dependent. The examples of the non-specific immunity are fever, phagocytosis by macrophages, skin and mucus. The example of the specific immune response is cytotoxic T-cells able to recognize antigens on infected cells and kill them before the infection could spread.
Earth would basically look like the Moon; minus the craters, of course. This is because with no atmosphere to hold all of the Oxygen near the surface, all life would die off fairly quickly.
