sentence: Some algae are protists, if they are single-celled.
sentences_before: Most protists are very small.
sentences_after: Many protists are part of the plankton and are very important for the ecosystem. The cells found in protists may be extremely complex, and are often little understood. It is now possible to do DNA sequencing, and a number of protists have been analysed. The results show that the Protista is not a monophyletic group. It is paraphyletic, and not a single clade.
concept_name: algae
headings: Protist
categories: Cell biology