KingdomKingdom ProtistaProtista CH. 20CH. 20

Evolution of Evolution of Eukaryotic LifeEukaryotic Life

ENDOSYMBIONT THEORYEarly eukaryotes developed symbiotic relationships with prokaryotic cellsProkaryotic cells lived inside eukaryotic cellsOver time, the smaller prokaryotic cells evolved with the eukaryotic cells to become mitochondria and chloroplastsEndosymbiosis 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 Major classes of ProtistsProtists–– AnimalAnimal--like like protistsprotists–– PlantPlant--like like protistsprotists–– FungusFungus--like like protistsprotists

Plant-like Protists• All are autotrophic-meaning they can make

their own food

• Examples:EuglenaAlgae

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 EuglenaDraw and Label the Euglena

More EuglenasMore Euglenas

MulticellularMulticellular: Algae: Algae

•• Are not generally true Are not generally true multicellularmulticellular organisms, but rather "colonies"organisms, but rather "colonies"

•• Show beginnings of specialized functions / Show beginnings of specialized functions / tissuestissues

•• 3 types 3 types –– Green algaeGreen algae–– Red AlgaeRed Algae–– Brown algaeBrown algae

Brown Brown AlgeaAlgea::

Giant Kelp ForestGiant Kelp Forest

VolvoxVolvox: a green colonial algae: a green colonial algae

Red Red algealalgeal bloombloom

Animal-like Protists

• Are all heterotrophs

• Classified by how they move.

• Examples:AmoebaParamecium

Amoeba

Moves using pseudopods- “false feet”- cytoplasmic projections

Found in freshwater

Pseudopods

They also use pseudopods for feeding

Amoeba Paramecium

Pseudopod

Pseudopod

Food Vacuole

Draw and label the AmoebaDraw and label the Amoeba

More amoebasMore amoebas

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 Draw and Label the Label the ParameciumParamecium ……

Your teacher Your teacher will be will be coming coming around to around to check!!!!check!!!!

More ParameciumMore Paramecium

Fungus like Protists:

•• Fungus like Fungus like ProtistsProtists::• All are external heterotrophs.

–– Act as Act as decomposersdecomposers–– Often have a slimy appearance/texture, hence Often have a slimy appearance/texture, hence

their name.their name.–– 2 types: 2 types:

•• Slime moldsSlime molds•• Water moldsWater molds

Water moldsWater molds:

•• Water molds:Water molds:–– Completely aquaticCompletely aquatic–– Often Often

decomposersdecomposers–– Sometimes Sometimes

parasiticparasitic

Water mold attacking a fishWater 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.

http://upload.wikimedia.org/wikipedia/commons/5/5d/Dog_vomit_slime_mold.jpg

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) (10-

100 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

3.5-4.0 bya

–

First prokaryotes appear

2.0-2.5 bya

–

Photosynthetic prokaryotes begin producing oxygen

1.5-2.0 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 – TrypanosomaSkin 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 cruziFever, severe heart damageBite 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.