Which of the following is the monomer of a nucleic acid?

• A. Nucleotide
• B. Amino acid
• C. Fatty acid
• D. Monosaccharide

Answer: (A)

Verified step by step guidance

1. Step 1: Understand the structure and function of nucleic acids. Nucleic acids, such as DNA and RNA, are macromolecules responsible for storing and transmitting genetic information. They are composed of repeating units called monomers.
2. Step 2: Recall the definition of a monomer. A monomer is the smallest unit that can join together to form a polymer. For nucleic acids, the monomer is a nucleotide.
3. Step 3: Examine the components of a nucleotide. A nucleotide consists of three parts: a phosphate group, a pentose sugar (either ribose or deoxyribose), and a nitrogenous base (adenine, guanine, cytosine, thymine, or uracil).
4. Step 4: Compare the given options. Amino acids are monomers of proteins, fatty acids are components of lipids, and monosaccharides are monomers of carbohydrates. None of these are related to nucleic acids.
5. Step 5: Conclude that the correct answer is 'Nucleotide,' as it is the monomer that forms nucleic acids through phosphodiester bonds.