AP BIOLOGY

Detailed explanation-1: -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. Using electrophoresis, we can see how many different DNA fragments are present in a sample and how large they are relative to one another.

Detailed explanation-2: -These DNA size standards can be used as positive controls for electrophoresis and for determining the sizes of unknown DNA fragments.

Detailed explanation-3: -Gel electrophoresis and DNA DNA is negatively charged, therefore, when an electric current is applied to the gel, DNA will migrate towards the positively charged electrode. 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-4: -Electrophoresis is a laboratory technique used to separate DNA, RNA or protein molecules based on their size and electrical charge. An electric current is used to move the molecules through a gel or other matrix.