The kingdom monera has been separated into two domains, the archaea and the bacteria. which of the following was most important in prompting scientists to change the way these organisms were classified? major differences were discovered in the structure and operation of the different species of monera. so many new species of monera were discovered that the kingdom got too large and needed to be separated. advances in technology revealed that some species of monera had nuclei and some did not. some species of monera were found that could live in colonies rather than as single cells.