Protists

Ch.25

Protist

DiverseEukaryotesUni or multicelledVarying body plans and movement

History

First eukaryotic organisms on Earth about 2 byaKingdom Protista (greek for first)

Classifying Protists

Based on feeding:1. Animal-like protists - heterotrophs2. Plant-like protists - photosynthesis

(autotrophs)3. Fungus-like protists - external

digestion (decomposer/parasite)

Characterized By:

Body plan (uni or multicellular)Means of obtaining food (autotrophs vs heterotrophs)Motility (flagella, cilia, or pseudopods)

Reproduction

Most asexually: (genetically identical) binary fission multiple fission

Sexually conjugation

Animal-like Protist4 Phyla:

1. Sarcomastigophora (zooflagellates)2. Protozoa (sarcodines)3. Ciliophora (ciliates)4. Apicomplexa (sporozoans)

Zooflagellates

Swim w/ flagella (long whip-like tails)

Have 1 or 2

Sexual or AsexualMany are free livingSome parasitesEx: Trypanosoma, African sleeping sickness

Sarcodines

Move thru pseudopods (“false feet”)– Extensions of cytoplasm– Prey on smaller cells

(bacteria)

AsexualExs: Amoebas, formanifera

CiliatesMove cilia (hairs)Ponds and slow moving streamsAsexualSome conjugate (exchange genetic material) - not repro.Exs: Paramecium

Characteristics

PellicleOral grooveMouth poreGullett

Anal poreContractile VacuolesMacronucleusMicronucleus

Sporozoan

Parasites4000 adult forms with no locomotionComplex life cycle (both asexual and sexual)SporozoitesEx: Plasmodium (malaria)

Animal Like Protist Diseases

MalariaAfrican sleeping sickness (Trypanosoma)Amebic dysentery (Entamoeba)Giardia

Plant-like Protists

Phyla:1. Euglenophyta (Euglenophytes)2. Chrysophyta (Chrysophytes/Golden Algae)3. Bacillariophyta (Diatoms)4. Dinoflagellata (Dinoflagellates)5. Rhodophyta (Red Algae)6. Phaeophyta (Brown Algae)7. Chlorophyta (Green Algae)

Euglenophytes

Flagella, chloroplast, no cell wall, eyespotChange shapeBinary fissionSwimmersExs: Euglena

ChrysophytesYellow-green algae, golden brown algaeGold colored chloroplastsMost live in freshwater/few in marineCan form cyst in harsh conditions

Diatoms

Cells walls of silicon (glass)Patterns & lines etched in glass cell walls (shine)Producers in freshwater marine websRelease atmospheric oxygen

Dinoflagellates

2 flagellaCell walls (looks like armor)Luminescent (give off light)Red Tide (toxic)

Red Algae

Deep in oceansMost multi-celledForm coral reefsPhotosyntheticMost marine seaweeds

Brown Algae

Dark yellow, brown colorLargest & most complex algaeMuti-celled, marine, cool temp waterEx: Kelp, Sargassum, Rockweed

Green Algae

PhotosyntheticCell wall = cellulose# of body forms (single celled, colonies, filaments, and multicellularExs: Chlamydomonas, Volvox, Ulva

Phytoplankton

Photosynthetic protists near ocean surfaceHalf of photo on Earth

Fungus-like Protists

TypesPhyla:1. Myxomycota (Slime Molds)2. Oomycota (Water Molds)

Slime Molds

Damp, rich organic matter (forest floor, compost)Forms stalks with sporesRecycle organic material

Water Mold

Eat dead matter in water (like dead fish with white fuzz)Caused great potato famine in Ireland