How are macromolecule polymers assembled from monomers? how are they broken down?

Macromolecule polymers are created by a dehydration process, one monomer has an -OH that is loss and another has an -H that is loss. The two monomers then bind, and an H2O molecule is generated. Macromolecules are broken down by hydrolysis, wherein an H2O molecule is cleaved to make -OH and -H. Then where the two molecules are joined, it is cleaved and an -OH and -H are attached to either one of the two molecules. This is dependent on the molecules, then two monomers have formed.

What’s the question

The bystander effect  for some reason my history teacher was talking about this