What is a Protist?
• Eukaryotic organism that is not a plant, animal, or fungi,
but may contain characteristics of any of them
Major Characteristics
• Protists don’t fit into any other kingdom so their
characteristics vary widely
Cell Type: eukaryotes
Cell Structure: have cell walls & cell membranes,
nuclei, some have chloroplasts, flagella, or cilia
Body Plan: most unicellular, some multicellular
Metabolism: autotrophs or heterotrophs
Reproduction: sexual or asexual
Organization of Kingdom—placed out convenience,
not based on any ancestry
• Animal-like protists: protozoa—ingest food by phagocytosis,
mouth-like structures or use pseudopods to move and engulf
prey
• Plant-like protists: algal protists—photosynthetic, contain
chlorophyll, carotenoids, other pigments
• Fungus-like protists: sporozoans—immobile, heterotrophic,
reproduce sexually in 1 host and then asexually in the next,
parasitic
Algal protists (plant-like)
Euglena—protozoa
(animal-like)
Sporozoan (fungus-like)
Protists and Disease
• Many protists are spread by mosquitoes
and flies when they bite
• They are parasites in humans
• Protists cause: malaria, African sleeping
sickness, as well as others that are often in
dirty water
Major Characteristics
•
•
•
•
Live everywhere
Type of fungus in soil depends on plant type
Nonvascular organisms
More closely related to animal kingdom than plant kingdom
Cell Type: Eukaryotes
Cell Structure: have cell walls, may have
chloroplasts, small nuclei w/little repetitive DNA
Body Plan: multicellular
Metabolism: heterotrophs
Reproduction: sexual and asexual
4 Major Phyla:
• Chydridiomycota: mostly aquatic
• Zygomycota: common black bread mold; important
decomposers of dead organic matter
• Ascomycetes: Mildew and yeast; Morels are highly prized
for their flavors and can cost hundreds of dollars per
ounce; largest group of fungus with over 60,000 species
• Basidiomycetes: mushrooms; majority are underground
until they need to reproduce