LIFE SCIENCE

Detailed explanation-1: -A nucleotide is the basic building block of nucleic acids (RNA and DNA). A nucleotide consists of a sugar molecule (either ribose in RNA or deoxyribose in DNA) attached to a phosphate group and a nitrogen-containing base. The bases used in DNA are adenine (A), cytosine (C), guanine (G) and thymine (T).

Detailed explanation-2: -A nucleotide consists of a sugar molecule, a nitrogenous base, and a phosphate group.

Detailed explanation-3: -Nucleotides are the building blocks of nucleic acid.

Detailed explanation-4: -The sugar-phosphate backbone forms the structural framework of nucleic acids, including DNA and RNA. This backbone is composed of alternating sugar and phosphate groups, and defines directionality of the molecule.

Detailed explanation-5: -A unit composed of sugar and nitrogen base linked by the glycosidic bond is nucleoside.