PATHOLOGY

Detailed explanation-1: -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-2: -Gel electrophoresis runs a current from negative at the top of the gel to positive at the bottom of the gel.

Detailed explanation-3: -Why do the fragments of DNA in gel electrophoresis move away from the negative cathode? DNA is negatively charged and attracted to the positive anode. DNA is positively charged and attracted to the positive anode.

Detailed explanation-4: -DNA consist of a phosphate backbone which is a negatively charged, hence when the DNA is placed in gei-electrophoresis it always moves towards anode, as the anode is positively charged.

Detailed explanation-5: -In the well, DNA is a negatively charged molecule due to the phosphate groups that constitute the backbone of DNA. Therefore, by placing the DNA at the negative end of the gel matrix, when the current is turned on the DNA will migrate down the gel towards the positive side because the opposite charges attract.