Final answer:
Nucleic acids like DNA and RNA are poly-anions due to their negatively charged phosphate backbone, making them significant in biological processes and drug delivery systems.
Step-by-step explanation:
Nucleic acids like DNA and RNA are indeed poly-anions. This is because they have a backbone made of sugar and phosphate groups; the phosphate groups are negatively charged at physiological pH. When many such nucleotides link together to form a polynucleotide chain, the multiple phosphate groups contribute to the overall negative charge, making DNA and RNA polyanions. This polyanionic character is significant in biological processes, such as the interaction with polyamines, which can stabilize DNA and RNA structures, and is also considered when developing drug delivery systems that target nucleic acids.