What term describes the structure of DNA as two twisted strands?

• A. Polynucleotides
• B. Replication Fork
• C. Double Helix
• D. Base Pairs

Answer: (C)

Two twisted polynucleotide strands describe DNA’s structure, which is known as the double helix. The two long polymers wrap around each other in a right-handed coil, with the sugar-phosphate backbones on the outside and the paired bases stacked inside. Complementary base pairing—adenine with thymine and guanine with cytosine—holds the strands together, while the antiparallel orientation means the two strands run in opposite directions. This arrangement not only defines the overall geometry but also underpins accurate replication and transcription. Polynucleotides refer to long single chains, base pairs describe the interior rung connections, and a replication fork is a temporary structure formed during copying, not the overall shape of the molecule.