Ans: Protists are a group with diverse organisms in it. In general, they are unicellular (having only one cell), microscopic organisms, but there could be exceptions. Protists have a highly organized cell with a nucleus and organelles (specialized cellular machinery). Earlier simple organisms like single-celled algae and amoeba were part of the single taxonomy category of kingdom Protista but as better genetic information emerged scientists have become more clear about different groups within protists and their evolutionary relationships. All eukaryotes that are not animals, fungi, or plants belong to the protists group.