Nucleotide:A nucleotide is a building block of DNA that consists of a sugar molecule (deoxyribose), a phosphate group, and a nitrogenous base.
Base Pairing: Base pairing refers to the specific hydrogen bonding between complementary nitrogenous bases (adenine with thymine, guanine with cytosine) in DNA molecules.
Double Helix:The double helix is the twisted ladder-like structure formed by two strands of DNA held together by hydrogen bonds between complementary base pairs.