Answer:
DNA's double helix shape allows for it to be copied efficiently and accurately through a process called DNA replication. Each DNA molecule is composed of two complementary strands of nucleotides, each containing a sugar, a phosphate group, and a nitrogenous base. The two strands of DNA are held together by hydrogen bonds between complementary nitrogenous base pairs, with adenine (A) always pairing with thymine (T), and guanine (G) always pairing with cytosine (C).
During DNA replication, the two strands of the double helix are separated by an enzyme called helicase, which breaks the hydrogen bonds between the complementary base pairs. Once the strands are separated, another enzyme called DNA polymerase adds nucleotides to each of the exposed strands, using the original strand as a template. The nucleotides are added in a complementary manner, with A always pairing with T and G always pairing with C.
The nucleotides are then linked together by covalent bonds between the sugar and phosphate groups, creating a new strand of DNA. As a result, each of the original DNA strands serves as a template for the synthesis of a new complementary strand, leading to two identical copies of the DNA molecule. This process of copying DNA is highly efficient and accurate due to the complementary base pairing rules and the specificity of the enzymes involved in DNA replication.