Early Indus Valley Civilization ... their Geograhpy, their customs and Indo-Aryan civilization with the earliest caste system.
Antibodies contribute to immunity in three main ways: they can prevent pathogens from entering or damaging cells by binding to them; they can stimulate removal of a pathogen by macrophages and other cells by coating the pathogen; and they can trigger direct pathogen destruction by stimulating other immune responses such as the complement pathway.
Antibodies are proteins secreted by specific cells of the immune system, which bind to foreign substances, known as antigens, to destroy them. A diseased condition arises when the bodyâs immune system mistakenly starts recognizing its own red blood cells (RBCs) as antigens and initiates their destruction. In this process antibodies produced by the immune system bind to the RBCs and destroy them.