1) Because bacteria are too small to classify and it needs more higher microscope to do that. 

2) All bacteria have the same nucleic acid in there body, so those thing are very hard too classify because it was too small and all look petty same for that acid in their body. 
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Because bacteria can't b seen through naked eye as they r vry smal .. So v need to use microscope fr dat. Hope I helped u.. Plz mark as the BRAINLIEST answer..
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