unicellular
Most protists are so small that they can be seen only with a microscope. Protists are mostly unicellular one-celled eukaryotes. A few protists are multicellular many-celled and surprisingly large. For example, kelp is a multicellular protist that can grow to be over 100-meters long Figure below . Multicellular protists, however, do not show cellular specialization or differentiation into tissues. That means their cells all look the same and, for the most part, function the same. On the other hand, your cells often are much different from each other and have special jobs.