Kingdom Protista CH. 20

Evolution of Eukaryotic Life ENDOSYMBIONT THEORY Early eukaryotes developed symbiotic relationships with prokaryotic cells Prokaryotic cells lived inside eukaryotic cells Over time, the smaller prokaryotic cells evolved with the eukaryotic cells to become mitochondria and chloroplasts Endosymbiosis Video

Basic Characteristics of the Kingdom Protista What are PROTISTS?? 1. Eukaryotic- it has a nucleus and membrane bound organelles 2. Unicellular (except ALGEA is multicellular) Protists are separated into three groups according to how they obtain energy. Major classes of ProtistsMajor classes of Protists –Animal-like protists –Plant-like protists –Fungus-like protists

Plant-like Protists All are autotrophic-meaning they can make their own food Examples: Euglena Algae

Euglena Euglena contain: chloroplasts, a flagella, and an eyespot to sense where light is. Unique because they are both heterotrophic and autotrophic. Draw and Label the Euglena

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Multicellular: Algae Are not generally true multicellular organisms, but rather "colonies"Are not generally true multicellular organisms, but rather "colonies" Show beginnings of specialized functions / tissuesShow beginnings of specialized functions / tissues 3 types3 types –Green algae –Red Algae –Brown algae

Brown Algea: Brown Algea: Giant Kelp Forest Giant Kelp Forest Volvox: a green colonial algae Red algeal bloom

Animal-like Protists Are all heterotrophs Classified by how they move. Examples: Amoeba Paramecium

Amoeba Moves using pseudopods- “false feet”- cytoplasmic projections Found in freshwater Pseudopods

They also use pseudopods for feeding Amoeba Paramecium Pseudopod Food Vacuole

Draw and label the Amoeba

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Have contractile vacuoles to pump out freshwater diffusing in due to osmosis. -Move using Cilia Paramecium

Paramecium- move using cilia (tiny hairlike projections) Draw and Label the Paramecium … Your teacher will be coming around to check!!!!

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Fungus like Protists: Fungus like Protists:Fungus like Protists: All are external heterotrophs. –Act as decomposers –Often have a slimy appearance/texture, hence their name. –2 types: Slime moldsSlime molds Water moldsWater molds

Water molds Water molds: Water molds:Water molds: –Completely aquatic –Often decomposers –Sometimes parasitic Water mold attacking a fish

Slime molds upclose Water and Slime molds are not in the Kingdom Fungi because their cell walls are made up of cellulose not chitin.

Review of prokaryotic & eukaryotic characteristics:  DNA in eukaryotic cells is contained in a nucleus; DNA in prokaryotic cells is not membrane bound and the cells do not have nuclei.  Eukaryotes have a variety of organelles, some of which are separated from the cytoplasm by membranes; prokaryotes do not have membrane- bound organelles.  Eukaryotes are composed of large cell(s) ( micrometers); most prokaryotes are small cells (1-10 micrometers)

The Evolution of the Eukaryotic Cell Review of major events in the history of life on Earth:  4.6 billion years ago (bya) – Earth formed  bya – First prokaryotes appear  bya – Photosynthetic prokaryotes begin producing oxygen  bya – First eukaryotes appear  700 million years ago – First multicellular life appear **No intermediate forms between prokaryotes and eukaryotes have been discovered.

DISEASES CAUSED BY PROTISTS MALARIA – Plasmodium –Causes severe chills, fever, sweating, confusion, and great thirst. –Spread from person to person by the anopheles mosquito.

Amoebic dysentery –Entamoeba histolytica –Amoebas feed on intestinal lining, causing bloody diarrhea. –Contaminated food or water.

Giardiasis – Giardia lamblia –Cramps, nausea, diarrhea, and vomiting –Contaminated water Leishmaniasis – Trypanosoma Skin sores and deep, eroding lesions. Bites from sand flies.

Sleeping sickness –Trypanosoma gamiense –Traypnaosoma rhodesiense –Fever, weakness, lethargy –Bite from infected insects such as tsetse fly. Chagas’ Disease – Trypanosoma cruzi Fever, severe heart damage Bite from infected kissing bug.

Toxoplasmosis – Toxoplasma gongii –Primary danger is fetal infection; can cause convulsions, brain damage, blindness, and death in fetuses. –Contact with infected cats or improperly cooked meat.