What are protists?
A type of organism
Protoctista is a kingdom in the taxonomic hierarchy that falls under the Eukarya domain. They are mostly unicellular but some are multicellular such as algae and seaweed. They share the same characteristics as eukaryotic cells; 80s ribosomes, membrane bound organelles including a nucleus etc. Most protoctists are autotrophic (make their own food) and some are heterotrophic (feed off other organisms).