What are the building blocks of nucleic acids?

Nucleic acids, such as DNA and RNA, are primarily composed of nucleotides, which serve as their fundamental building blocks. Each nucleotide consists of three components: a phosphate group, a five-carbon sugar (ribose in RNA and deoxyribose in DNA), and a nitrogenous base (which can be adenine, thymine, cytosine, guanine, or uracil). This structure allows nucleotides to link together through phosphodiester bonds, forming the long chains that make up the nucleic acid polymers.

In this context, the other options represent different categories of macromolecules: fatty acids are the building blocks of lipids; amino acids serve as the building blocks of proteins; and monosaccharides are the simplest sugars that form carbohydrates. While each of these components is essential for various biological functions, they do not contribute to the structure of nucleic acids. Thus, the correct identification of nucleotides as the building blocks of nucleic acids highlights their unique and integral role in the storage and transmission of genetic information.