AP BIOLOGY

Detailed explanation-1: -Gel electrophoresis is a laboratory method used to separate mixtures of DNA, RNA, or proteins according to molecular size. In gel electrophoresis, the molecules to be separated are pushed by an electrical field through a gel that contains small pores.

Detailed explanation-2: -All DNA molecules have the same amount of charge per mass. Because of this, gel electrophoresis of DNA fragments separates them based on size only.

Detailed explanation-3: -Smaller molecules migrate through the gel more quickly and therefore travel further than larger fragments that migrate more slowly and therefore will travel a shorter distance. As a result the molecules are separated by size.

Detailed explanation-4: -Electrophoresis is a process that enables the sorting of molecules based on size. Using an electric field, molecules (such as DNA) can be made to move through a gel made of agarose or polyacrylamide.

Detailed explanation-5: -These DNA size standards can be used as positive controls for electrophoresis and for determining the sizes of unknown DNA fragments.