SNP genotyping is the measurement of genetic variations of single nucleotide polymorphisms (SNPs) between members of a species. It is a form of genotyping, which is the measurement of more general genetic variation.
On most plays, the center will snap the ball directly into the quarterback's hands. In a shotgun formation, the center snaps the ball to the quarterback lined up several yards behind him.
The quarterback is the player who receives the ball from the center to start the play. The most important position on the offensive side, the quarterback is usually responsible for receiving the play from the coaches on the sideline and communicating the play to the other offensive players in the huddle.