AP BIOLOGY

Detailed explanation-1: -To separate DNA using agarose gel electrophoresis, the DNA is loaded into pre-cast wells in the gel and a current applied. The phosphate backbone of the DNA (and RNA) molecule is negatively charged, therefore when placed in an electric field, DNA fragments will migrate to the positively charged anode.

Detailed explanation-2: -The DNA molecules have a negative charge because of the phosphate groups in their sugar-phosphate backbone, so they start moving through the matrix of the gel towards the positive pole.

Detailed explanation-3: -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: -Because DNA and RNA are negatively charged molecules, they will be pulled toward the positively charged end of the gel.

Detailed explanation-5: -Gel electrophoresis runs a current from negative at the top of the gel to positive at the bottom of the gel. During gel electrophoresis, biological samples of DNA or protein are loaded in the top of the gel. A current is then run through the gel from negative to positive.