Download Protozoa - El Camino College

Classification
and
Protozoan Groups
There are about two million known
species of living organisms
What is a species?
members of populations that interbreed in nature
Appearance is not important
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Species has scientific name
Common names applied to species are often misleading.
A starfish is not a fish.
A sea horse is not a horse.
Scientific names are standard and recognized internationally
Scientific name has a two-word Latin name, like Homo sapiens
The first word is the genus to which the organism belongs, Homo, means man
The second word represents the species, sapiens, means wise or thinking
Variations that you might find: H. sapiens or Homo sp.
We have classified species into groups
A classification system brings logic and order to the study of living things.
Characteristics used for classification:
characteristics that reflect the relationships between the species:
shared characteristics
allow to group species
unique characteristics
allow to separate species
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Hierarchical Classification
Did King Phillip Come Over For Good Soup?
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Domains
Kingdoms
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Protozoans: animal-like protists
Heterotrophs by ingestion (ingest their food)
Movement at one stage of their life cycle
cilia, flagella or pseudopodia
Carry on all life activities within
a single cell (unicellular)
Very important ecologically
At least 10,000 species of protozoa are symbiotic in or on other plants or animals
Relationships may be mutualistic, commensalistic, or parasitic
Protozoans: form and function
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Protozoans with flagella: Euglena
Euglena
•Freshwater with abundant vegetation
•Flagellum extends anterior end
• Chloroplasts
•Stigma functions in orientation to light
•Normally autotrophic, but can make
use of abosrb nutrients
Protozoans with flagella: Termite symbionts
Trichonympha
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Protozoans with flagella: Giardia
It's estimated that between 1% and 20%
of the U.S. population has giardiasis,
and this figure may be 20% or higher in
developing countries, where giardiasis
is a major cause of epidemic childhood
diarrhea.
Giardia is becoming ubiquitous in
pristine areas like springs and streams
Protozoans with flagella: Trypanosoma
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Sleeping sickness
Chaga’s disease
Protozoans with cilia: Paramecium
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Protozoans with cilia: Vorticella
Protozoans with pseudopodia: Amoeba
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Protozoans with pseudopodia: Entoamoeba
Entoamoeba
Entamoeba histolytica is the pathogen
responsible for 'amoebiasis‘
It is estimated to infect about 50 million
people worldwide.
And to cause 70,000 deaths per year
world wide
Protozoans with apex: Plasmodium
Most important infectious disease of humans
About 3.3 billion people - half of the world's
population - are at risk of malaria.
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Importance of Protozoans
In water:
-form part of plankton
-feed on bacteria and other protista
-food for filter feeders, like oysters and mussels
In soil:
-feed on bacteria
- release excess nitrogen that plants use
Symbiosis:
- Mutualism
- Parasitism
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