A SNP is a variation of a single nucleotide between individuals. These polymorphisms can therefore be used to discern small differences both within a population and among different populations.
President of the United States. The President of the United States is the head of state of the U.S., the chief executive of the federal government, and Commander-in-Chief of the armed forces. The United States was the first nation to create the office of President as the head of state in a modern republic.
US Presidents Parent Category: History of the United States The US President is the head of state and the head of the federal government of the United States of America. The president's power is checked and balanced by the two other branches of the US Government, which are Congress and the Supreme Court.