The two main components of blood are: Cells or cell-like bodies: These include Erythrocytes, Leukocytes and thrombocytes ( Thrombocytes are not cells but pieces of large cells called megakaryocytes.)...
The bloods Plasma is needed because without it nothing would flow. Red Blood Cells are very large and trying to pump them through air (ie if there was not plasma) would be impossible. Not to mention...