Each is really a separate branch on the eukaryotic tree. Thy used to be thought of as fungii, but they are not at all related to them. They are amoeboid soil organisms. Cellular slime molds e.g. Dictyostellium , with a life cycle very much like the Myxobacteria . Acellular slime molds Diploid phase - masses of cytoplasm with many nucleii but no membrane separating individual cells.
Spores germinate into haploid individual cells.
This phase is usually transient, and they can be thought of a gametes. These are the ciliates, dinoflagellates, and apicomplexans. They are a very diverse group of organisms, but all have vesicular membrane structures underneath their cell membrane, and are all related by ancestry. The apicomplexans are not well studied except Plasmodium , the causative agent of malaria, probably the single most important disease in man. Ciliates e.g. Paramecium .