Should a sudden power outage occur, or I neglect to save the material to the hard drive, it would all be lost. However, if I am satisfied with this writing, it will be permanently saved to the hard drive, available for use at a later time. Your genetic heritage is your biologic hard drive. One of the 'saved' pieces of information is your blood type. In genetic lingo, the blood type variations are known as alleles.
Every person contains alleles-alternate forms of genes.
The alleles determine whether you have blue eyes or brown, are tall or short, have black hair or red, and other distinctions. That means there are three variations, or alternatives, for your blood type. However, the influence of your blood type is far greater than that of the gene that gives you eye color. Much of that influence has to do with its location and the way it interacts with other genes. The gene for ABO blood type is located on the q leg of chromosome number 9, around band 34.