What types of bond (linkage) are present in nucleotide?

Phosphodiester linkage

The correct answer is Option (3) → Phosphodiester linkage

A nucleotide consists of a nitrogenous base, a pentose sugar, and a phosphate group.
The characteristic linkage associated with nucleotides (especially in nucleic acids) is the phosphodiester linkage, which connects nucleotides together.

Let’s check the options:

• Peptide linkage  → found in proteins ---- Incorrect

• Ionic bond  → not characteristic of nucleotide structure ---- Incorrect

• Phosphodiester linkage  → links nucleotides in DNA/RNA ------ Correct

• O-glycosidic linkage  → sugars in nucleotides are linked to bases by N-glycosidic, not O-glycosidic ----- Incorrect