Answer:
The given blank can be filled with protists.
Step-by-step explanation:
The organisms or species coming under the kingdom Protists are mainly unicellular, however, they also do comprise certain kinds of multicellular species. As mentioned in the question, the eukaryotes, which do not snug in other kingdoms are kept in this kingdom. As a consequence, even the members of the kingdom Protists do not share much of the similarities, as it comprises diverse species.