Animal-Like ProtistsHeterotrophicClassified by means of locomotion: flagella, cilia,

pseudopods, or none (sessile)Many free living, some parasites of humans and

animalsParamecium (many species) is free living

Animal-Like ProtistsPhylum Protozoa

Locomotion by pseudopodia cytoplasmic streaming/cyclosis amoeboid movement

Prey on bacteria, ingest food particles in water using pseudopodia vesicle, intracellular digestionSubphylum Sarcodina - amoebas: freshwater, marine

or soil; some have a test/shell around cell membraneSubphylum Mycetozoa – some have glassy shells

(radiolarians)

Simple tests (or shells) are made by either secretion or by the agglutination of foreign material or a combination of both. Environmental changes can be determined by analyzing the

composition of tests, including fossil tests, which may indicate past climatic conditions.

Testate Amoebas

Radiolarian (marine amoeba) shells

Animal-Like ProtistsPhylum Ciliophora

Locomotion by ciliaAsexual reproduction – binary fissionMost elaborate organelles of any protist:

Macronucleus that controls cell functionsMicronucleus exchanged through conjugation (sexual

reproduction)pellicle (elastic layer of protein) surrouding cell membraneFood acquisition: oral groove mouth pore gullet food

vacuolesExcretion: anal pore contractile vacuole

Animal-Like ProtistsPhylum Sarcomastigophora

One or more flagellaSubphylum Mastigophora – many free living, some parasites

genus Trypanosoma Infect blood in many vertebratesTransmitted by insect vectors

Ex.: African sleeping sickness, caused by two species of trypanosomes, transmitted by tse-tse fly fever, lethargy, eventual coma, death;Giardia – found in fresh water gastrointestinal disease

Tsetse fly (vector)

Trypanosomes in human blood

Giardia lamblia causes giardiasis, an intestinal infectionFound in freshwater – streams & riversCysts carried in animal feces

Animal-Like ProtistsPhylum Apicomplexa (former sporozoans)

no adaptations for locomotion all animal parasitesApical complex = organelles specialized for entry into host

cells/tissuesComplex life cyles with sexual and asexual stages, often more

than one hostPlasmodium – mosquito vector malariaToxoplasma gondii – affects developing fetuses, newbornsCryptosporidium – found in water, animal feces

gastrointestinal disease

Plasmodium faciparum

Malaria350–500 million

cases / year, killing one to three million

people

Malaria life cycle on UTube

Anopheles mosquito vector

http://upload.wikimedia.org/wikipedia/commons/d/db/Symptoms_of_Malaria.png

Fungus-Like ProtistsSlime Molds & Water MoldsUni- or multi-cellular, all heterotrophicSaprophytic, some parasitic

Fungus-Like ProtistsPhylum Myxomycota – Plasmodial Slime MoldsFeeding stage = Plasmodium, a

multinucleated (2n) mass of cytoplasmAmoeboid movement by

cytoplasmic streamingphagocytosis of decaying

matterReproductive state = Fruiting

bodies produce haploid spores by meiosisSpores produce haploid (n)

reproductive cells that fuse (2n)mitosis w/o cytokinesis

multinucleated plasmodium (unicellular)

Physarum life cycle

Fungus-Like ProtistsPhylum Dictyostelida – Cellular Slime Molds

Individual haploid cells live independentlyScarcity of food triggers release of chemical that

attract othersMany cells gather to form a multi-cellular

pseudoplasmodium – (each cell retains its membrane) develops fruiting bodies haploid spores new independent haploid cells

How do cellular slime molds differ from plasmodial slime molds?

Fungus-Like ProtistsPhylum Oomycota – Water MoldsAsexual reproduction -- flagellated zoospores

threadlike cellsSexual reproduction – egg and sperm produced

fertilization tubes zygote threadlike cells

Water mold on dead mayfly larva

Fungus-Like ProtistsPhylum Chytridiomycota – Water MoldsMost unicellular, parasiticMake flagellated gametes

and zoosporesChitin in cell walls,

filamentous cells, enzymes and biochemistry similar to fungi some classify them in

kingdom Fungimay be a transitional

form between protists and fungi

Healthy Tasmanian frog

Infected frog

Chytrid (microscopic)