In DNA structure, which molecules are the building blocks (monomers) of DNA?

• A. Fatty acids (components of phospholipid membranes)
• B. Nucleotides (each consisting of a deoxyribose sugar, a phosphate group, and a nitrogenous base)
• C. Monosaccharides (simple sugars that polymerize into polysaccharides)
• D. Amino acids (linked by peptide bonds to form polypeptides)

Answer: (B)

Verified step by step guidance

1. Understand that DNA is a polymer, meaning it is made up of repeating smaller units called monomers.
2. Identify the type of monomer that makes up DNA by recalling the structure of DNA: it consists of a sugar, a phosphate group, and a nitrogenous base.
3. Recognize that the monomers of DNA are called nucleotides, each composed of three parts: a deoxyribose sugar, a phosphate group, and a nitrogenous base.
4. Differentiate nucleotides from other biological molecules such as fatty acids (which are components of membranes), monosaccharides (which form polysaccharides), and amino acids (which form proteins).
5. Conclude that nucleotides are the correct building blocks (monomers) of DNA because they polymerize to form the DNA strand.