The monomers that are called nucleotides are the building blocks of nucleic acids.

There are two main types of nucleic acids:

* Deoxyribonucleic acid (DNA), which carries the genetic instructions for the development and function of all living organisms.

* Ribonucleic acid (RNA), which plays a vital role in protein synthesis and other cellular processes.

Nucleotides consist of three components:

1. A nitrogenous base: There are five main nitrogenous bases found in DNA and RNA:

* Adenine (A)

* Guanine (G)

* Cytosine (C)

* Thymine (T) - found only in DNA

* Uracil (U) - found only in RNA

2. A five-carbon sugar:

* Deoxyribose in DNA

* Ribose in RNA

3. A phosphate group: This group is attached to the 5' carbon of the sugar.

These three components are linked together by covalent bonds to form a nucleotide.

So, in summary, nucleotides are the monomers that make up nucleic acids (DNA and RNA).