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Protists
Protist Characteristics
An extremely diverse group
Eukaryotes Mostly unicellular
some colonial some multicellular
Some heterotrophic, some autotrophic, some both
Some have cell walls
3 Major Types
Animal-like protozoa
Fungus-like
Plant- like algae
“Animal-Like” Protists
Protozoans Are heterotrophs (some are parasites!)
Types of protozoans: 1. sarcodines2. ciliaphore3. flagellates4. sporozoans
Protist Phyla
1. Sarcodines – use pseudopodia (“false feet”) to move and get food
EX: Amoebas, foraminifera. radiolarians
http://www.funsci.com/fun3_en/protists/exhibition.htm
Amoeba change forms continuously
2. Ciliophores – use cillia to move
EX: paramecium
http://www.funsci.com/fun3_en/protists/exhibition.htm
Paramecia
http://ebiomedia.com/gall/ciliates/index.html - more ciliates
3. Flagellates- have whip-like flagella
This flagellate lives in termite gut – digests cellulose.
This one is a pathogen – causes diarrheaEX: Giardia
Dinoflagellates have 2 flagella
A related protist, Leishmania, causes the disease leishmaniasis.
These protists are transmitted by biting flies, and are a serious public health problem in much of the world.
Leishamanasis
4. Sporozoans – no method of movement
form spores, many are parasitesEX:
- Toxoplasma- carried by rodents, birds, and domestic cats (can be harmful to unborn babies if mom changes the kitty litter box)
- Plasmodium- causes Malaria (carried by mosquitoes)
Life Cycle of Malaria
“Plant-like” protists
Are autotrophs
Mostly algae
Are classified by their pigments (their color) – red, green or brown
Many are multicelled
Do not have stems, leaves and roots like plants
Make up phytoplankton (bottom of ocean food chain)
Plant like protists
1. Green Algae
Are green in color Ex –
Spirogyra
Spirogyra
http://www.funsci.com/fun3_en/protists/exhibition.htm
Desmid- unicellular green algae
Green algae - Volvox
Green algae - Haematococcus Turns birdbath red
2. Red Algae
Multicellular Commonly called sea weed Live in deep salt water Are used by humans to help make ice cream
and hair conditioner Are eaten in some Asian cultures
3. Brown Algae
Multicellular Commonly called sea weed Thallus- plant-like seaweed
body Holdfast- root-like; anchors to
surface Stipe- stem-like Blades- leaf-like
Have air-filled sacs called air bladders
Used in many foods and beauty products
Diatoms
Photosynthetic protists Mostly marine Have silica (glass-like)
shell Used to make
reflective paint, toothpaste, and abrasives
“Fungus-Like” Protists
Slime & water molds
Some of these can move
Many are decomposers or parasites
Slime molds