PATHOLOGY

Detailed explanation-1: -Shorter strands of DNA move more quickly through the gel than longer strands resulting in the fragments being arranged in order of size.

Detailed explanation-2: -Supercoiled plasmid DNA, because of its compact conformation, moves through the gel fastest, followed by a linear DNA fragment of the same size, with the open circular form traveling the slowest.

Detailed explanation-3: -DNA samples are placed in a special gel and subjected to an electric field. Because DNA is negatively-charged, it moves toward the positive electrode. The DNA fragments that are shortest will travel farthest, while the longest fragments will remain closest to the origin.

Detailed explanation-4: -Supercoiled DNA migrates faster than predicted in an agarose gel due to its conformation. Supercoiled DNA is the desired species when isolating plasmid DNA.

Detailed explanation-5: -This means that a small DNA molecule will travel a greater distance through the gel than will a larger DNA molecule. As previously mentioned, gel electrophoresis involves an electrical field; in particular, this field is applied such that one end of the gel has a positive charge and the other end has a negative charge.