Growth

DNA (Deoxyribonucleic acid) is a double-stranded molecule composed of two long chains of nucleotides. These chains run in opposite directions and are held together by hydrogen bonds between complementary nitrogenous bases: adenine (A) pairs with thymine (T), and cytosine (C) pairs with guanine (G). The two strands form a double helix structure, which is the signature feature of DNA. Thus, DNA is composed of two strands of nucleotides that are held together by hydrogen bonds.