What do bacteria, algae and paramecium have in common?
Well, bacteria are eubacteria. Algae and paramecium are protists. Hm, wow, this is hard. I guess they’re both “lower” organisms but that’s about as far as it goes. They are not in the same kingdom, they are not microorganisms. (kelp, which is algae, is multicellular and very easy to see) They are not all prokaryotes. Only bacteria are prokaryotes. Bacteria do not necessarily have contractile vacuoles and algae don’t have flagella. And RNA polymerase really isn’t a good example since eubacteria only have one type and eukaryotes have many kinds. I think the point of the assignment was for you to figure out that they don’t have much in common.