Any eukaryotic organism that is not an animal, plant, or fungus is referred to as a protist.
Protists most likely originated from a common ancestor, but because other eukaryotes are not present, they do not constitute a natural group or clade.
Protists are broadly classified into:
Plant-like protists -
Algae are protists that resemble plants.
They consist of multicellular seaweed and single-celled diatoms.
Algae produce nourishment through photosynthesis and, like plants, possess chlorophyll. Red and green algae, euglenids, and dinoflagellates are different types of algae.
Animal-like protists-
Protozoa is the name for protists that resemble animals (singular, protozoan).
Most protozoa are made up of just one cell.
They resemble animals because they can move and are heterotrophs.
Despite not being animals, protozoa are regarded to be the ancestors of all living things.
Fungi-like protists -
Molds are fungus-like protists.
They consume decomposing organic debris as their primary food source.
They have a fungus-like appearance and reproduce by the release of spores.
However, they differ significantly from fungi in other aspects and resemble other protists.