Experiment II: DNA has: no charge. a supercharge. a positive charge. a negative charge.

DNA has a negative charge due to the phosphate groups present in its backbone. This is because each phosphate group contains a negatively charged oxygen atom, giving the entire DNA molecule its overall negative charge. This characteristic plays a crucial role in many biological processes, including the interaction of DNA with proteins and other molecules. In real-world applications, the negative charge of DNA is exploited in laboratory techniques such as gel electrophoresis. In this process, an electric field is applied to a gel containing DNA, causing the negatively charged molecules to migrate toward the positive electrode. This technique allows scientists to separate and analyze DNA fragments by size, providing valuable insights into genetics and molecular biology.