Surely the question (if it does mean “only one type of polyMER” is found in bacterial cells) is wrong. There are polypeptides, but bacterial cells also have other polymers - the bacterial chromosome and plasmids contain DNA (a polynucleotide) and RNA will be present also, again a polynucleotide. So, for the question to state that there is only one kind of polymer in bacterial cells is not true.
The cell wall in bacteria is made of peptidoglycan, which is not purely a sugar molecule, but does certainly contain polysaccharide molecules. So, if the OP was in fact correct in their wording of the question (which if they’re not, the question is stating something false), this is my best guess as to what a possible answer could be.