blood type. Any of the four main types into which human blood is divided: A, B, AB, and O. Blood types are based on the presence or absence of certain substances, called antigens, on red blood cells.Also called blood group.lood type. Any of the four main types into which human blood is divided: A, B, AB, and O. Blood types are based on the presence or absence of certain substances, called antigens, on red blood cells.
Amendments are sent to the legislatures of the states by default. Only one amendment, the 21st, specified a convention. In any case, passage by the legislature or convention is by simple majority. The Constitution, then, spells out four paths for an amendment:
Article 5 of the US Constitution describes how the Constitution may  be altered by proposing an amendment or amendments and subsequent  ratification. Thirty-three amendmentsâ¦ have been proposed and  twenty-seven of those have been ratified and are now part of the  Constitution.