How many strands make up a DNA molecule?

A DNA molecule is primarily composed of two strands that twist around each other to form a double helix. Each strand is made up of a sequence of nucleotides, which consist of a sugar, a phosphate group, and a nitrogenous base. The two strands are complementary and held together by hydrogen bonds between the nitrogenous bases, adhering to specific pairing rules (adenine pairs with thymine, and cytosine pairs with guanine). This structure is essential for the processes of replication and transcription, allowing genetic information to be accurately copied and expressed. The configuration of two strands is fundamental to the stability and function of DNA, facilitating its role in heredity and cellular operations.