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. sarcodines 2. ciliaphore 3. flagellates 4. 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 diarrhea EX: 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

form spores, many are parasites 4. Sporozoans – no method of movement form spores, many are parasites EX: - 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