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.
A free kick is also used to restart the game following a safety. The team that was trapped in its own end zone, therefore conceding two points to the other team, kicks the ball from its own 20-yard line. This can be a place kick (in the NFL, a tee cannot be used), drop kick or punt.