Question

proteins
response
a. what are the monomers of protein?
b. what does the velcro represent?

Explanation:

a. Proteins are polymers made up of amino - acid monomers. Amino acids are the building blocks of proteins.
b. Without further context about the "Velcro" in relation to proteins, it's hard to say for sure. But if it's used in a model, it might represent the intermolecular forces (such as hydrogen bonds, ionic bonds, etc.) that hold amino - acids together in a protein structure or the interactions between different parts of a protein molecule.

Answer:

a. Amino acids
b. Intermolecular forces in protein structure (assuming it's a model - related reference)