In some biological taxonomy schemes, protists are a large and diverse group of eukaryotic microorganisms, which belong to the kingdom Protista. There have been attempts to remove the kingdom from modern taxonomy but it is still very much in use. The use of Protoctista is also preferred by various organisations and institutions. Molecular information has been used to redefine this group in modern taxonomy as diverse and often distantly related phyla. The group of protists is now considered to mean diverse phyla that are not closely related through evolution and have different life cycles, trophic levels, modes of locomotion and cellular structures. Besides their relatively simple levels of organization, the protists do not have much in common. They are unicellular, or they are multicellular without specialized tissues, and this simple cellular organization distinguishes the protists from other eukaryotes, such as fungi, animals and plants.