LIFE SCIENCE

Detailed explanation-1: -DNA is negatively charged because of the presence of phosphate groups in nucleotides. The phosphate backbone of DNA is negatively charged, which is due to the presence of bonds created between the phosphorus and oxygen atoms.

Detailed explanation-2: -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-3: -Because DNA and RNA are negatively charged molecules, they will be pulled toward the positively charged end of the gel.

Detailed explanation-4: -In double-stranded DNA, the molecular double-helix shape is formed by two linear sugar-phosphate backbones that run opposite each other and twist together in a helical shape. The sugar-phosphate backbone is negatively charged and hydrophilic, which allows the DNA backbone to form bonds with water.