Monomers are the repeating units that join together to form polymers.

• A. Polymers
• B. Lipids
• C. Nucleotides
• D. Amino acids

Answer: (A)

Monomers are the building blocks that link to create polymers. The statement is describing the relationship: monomers join to form the larger, chain-like molecules known as polymers. Think of it this way—polymers are the result of polymerization, built from repeating units (the monomers) such as nucleotides in nucleic acids or amino acids in proteins. Lipids aren’t formed by linking repeating units in the same way, so they don’t fit the idea of monomers joining to form polymers. So, the term that best fits the description given is polymers—the product built from monomer units. If you were asked which specific molecules serve as monomers for particular polymers, you’d name nucleotides for nucleic acids or amino acids for proteins.