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.
As diagrammed with the Joe Theismann/Lawrence Taylor footage at the beginning of the movie (see below), Michael Oher's position on the football field is left tackle. It is the left tackle's job to protect the quarterback's blind side.