The following picture shows the ethidium bromide-stained bands obtained by gel electrophoresis of two samples digested with two different restriction enzymes. One of the DNAs is human genomic DNA, the other is the small genome of a bacteriophage (bacterial virus) that infects E. coli cells. One of the restriction enzymes is EcoRI (5' G^AATTC 3'); the other is HPa II (%' C^CGG 3'). For each of the four lanes on the gel (A-D), identify which of the two DNA samples was analyzed and which of the two DNA samples was analyzed and which of the two enzymes was used. The arrow represents the direction of electrophoresis. A B C D

The following picture shows the ethidium bromide-stained bands obtained by gel electrophoresis of two samples digested with two different restriction enzymes. One of the DNAs is human genomic DNA, the other is the small genome of a bacteriophage (bacterial virus) that infects E. coli cells. One of the restriction enzymes is EcoRI (5' G^AATTC 3'); the other is HPa II (%' C^CGG 3'). For each of the four lanes on the gel (A-D), identify which of the two DNA samples was analyzed and which of the two DNA samples was analyzed and which of the two enzymes was used. The arrow represents the direction of electrophoresis. A B C D