Protists

• What is a protist?

• Protist Diversity

• Diseases Caused by protists

Protists Have Complex Cells

• Eukaryotic-with a nuclear membrane

• Membrane bound organelles

• Single-celled and multicellular algae

Movement• Flagellum- whip-like tail

–Euglena, Dinoflagellates

• Cilia-hair-like projections that work like oars in water–Paramecium

• Pseudopods (false foot)–Amoeba

Amoeba

Paramecium

Paramecium

Diatoms

Diatoms

Dinoflagellate = red tide

Euglena

Algae

Spirogyra

Stentor

Vorticella

Volvox –colony protists

Respond to the environment

• Detect light, touch, and chemical changes in their environment.

• Eyespots and other organelles detect these changes

ReproductionBecause eukaryotes have

numerous chromosomes,

• Meiosis (gametes form)

• Mitosis (conjugation-joining gametes)

Evolutionary LinesProkaryotes• Heterotrophic

bacteria = mitochondria

• Autotrophic bacteria = chloroplasts

Eukaryotes• Plants evolve

from autotrophic protists

• Animals and fungi have evolved from heterotrophic protists

Autotrophic Protists• Microscopic Diatoms,

phytoplankton, zooplankton

• Brown, Green, Red algae are multi-cellular (sea weeds)

Heterotrophic Protists• Consumers• Slime molds, water molds• Amoeba, Paramecium, Stentor

(animal-like)• Trichonympha in termite guts• Plasmodium causes malaria

Diseases• Anopheles (mosquitoes) bite

infected animal.• Spores form in mosquito gut.• Spores are injected into host

and reproduce in blood cells.• Asexual spores infect liver and

burst out of cells

Diseases Caused by ProtistsDisease Host Organism

Amoebic dysentary

Humans Entamoeba

Malaria Toxoplamosis

Humans

Cats/humans

Plasmodium Toxoplasma

GiardiasisSleeping Sickness

Leishmaniasis

Humans

Tsetse flies

Sand flies

Giardia

Trypanosoma

Leishmania

Late blight Potatoes Phytophthora