Which of the following conclusions is most clearly supported by the structural representations of nucleic acids?

• A. Nucleic acids are formed by the polymerization of monosaccharides.
• B. Nucleic acids are made entirely of amino acids joined by peptide bonds.
• C. Nucleic acids contain fatty acid tails attached to a glycerol backbone.
• D. Nucleic acids are composed of nucleotide monomers linked by phosphodiester bonds.

Answer: (D)

Verified step by step guidance

1. Step 1: Begin by understanding the structure of nucleic acids. Nucleic acids, such as DNA and RNA, are polymers made up of repeating units called nucleotides. Each nucleotide consists of three components: a phosphate group, a five-carbon sugar (either deoxyribose in DNA or ribose in RNA), and a nitrogenous base.
2. Step 2: Analyze the incorrect options. The first option suggests that nucleic acids are formed by the polymerization of monosaccharides. This is incorrect because monosaccharides are the building blocks of carbohydrates, not nucleic acids.
3. Step 3: Evaluate the second incorrect option. It states that nucleic acids are made entirely of amino acids joined by peptide bonds. This is incorrect because amino acids are the building blocks of proteins, and peptide bonds are specific to protein structure.
4. Step 4: Examine the third incorrect option. It claims that nucleic acids contain fatty acid tails attached to a glycerol backbone. This is incorrect because fatty acids and glycerol are components of lipids, not nucleic acids.
5. Step 5: Identify the correct conclusion. Nucleic acids are composed of nucleotide monomers linked by phosphodiester bonds. These bonds form between the phosphate group of one nucleotide and the hydroxyl group on the sugar of another nucleotide, creating the sugar-phosphate backbone of the nucleic acid polymer.