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
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
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!!!!
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.
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.