What term describes the structure of DNA consisting of two complementary strands wound around each other?

What term describes the structure of DNA consisting of two complementary strands wound around each other?

• A. Double helix
• B. Single strand
• C. Triple helix
• D. Helix

Answer: (A)

DNA’s structure is a double helix—the two complementary strands twist around each other like a spiral staircase. The backbone forms the outside, while the bases pair in the middle, giving the characteristic two-strand, intertwined shape. A single strand describes only one chain; a triple helix would involve three strands; and helix alone doesn’t specify how many strands are present. So the term double helix precisely captures the two intertwined DNA strands.

DNA’s structure is a double helix—the two complementary strands twist around each other like a spiral staircase. The backbone forms the outside, while the bases pair in the middle, giving the characteristic two-strand, intertwined shape. A single strand describes only one chain; a triple helix would involve three strands; and helix alone doesn’t specify how many strands are present. So the term double helix precisely captures the two intertwined DNA strands.