Answer:
DNA sample is loaded at the negative end of the gel and is made to move towards the positive terminal present at the opposite end.
Explanation:
DNA is a polymer of deoxyribonucleotides. Each of deoxyribonucleotides has a nitrogenous base, phosphate, and pentose sugar. The presence of the phosphate groups imparts a negative charge to the sugar phosphate backbone of DNA. Since DNA is negatively charged, it should be loaded at the negative terminal of the gel electrophoresis chamber and should be made to move towards the positive terminal present at the other end of the apparatus.