Final answer:
The basic units of DNA made up of a sugar, a phosphate group, and a nitrogenous base are known as nucleotides. These nucleotides link together to form DNA's double helix structure.
Step-by-step explanation:
The basic units of the DNA molecule, composed of a sugar, phosphate, and one of four DNA bases, is called a nucleotide. Every nucleotide is made up of three essential components:
A nitrogenous base, which can be either a purine (adenine [A], guanine [G]) or a pyrimidine (cytosine [C], thymine [T]).
A pentose sugar, specifically deoxyribose in DNA.
A phosphate group (–PO4³–).
These nucleotides are the building blocks of DNA and RNA, arranging into sequences to encode genetic information. Nucleotides link together to form the DNA double helix structure, where the sugar-phosphate backbone is on the outside, and the nitrogenous bases are on the inside, pairing with complementary bases through hydrogen bonding.