Answer: double helix, composed of two complementary strands of nucleotides, twisted around each other in a spiral shape. The nucleotides are composed of a sugar molecule, a phosphate group, and a nitrogenous base, which can be adenine (A), cytosine (C), guanine (G), or thymine (T). The nitrogenous bases pair up in a specific way, with A always bonding with T and C always bonding with G, forming the "rungs" of the DNA ladder. This pairing provides the stability and specificity of the DNA molecule, allowing it to encode genetic information and transmit it from one generation to the next.
Step-by-step explanation: