Download Kingdom Protista

Kingdom Protista
The most diverse group of organisms
Discovery of Protists
• Anton van Leeuwenhoek
– Lived around 300 years ago
– First to use a microscope to
see cells
– “No more pleasant sight has
met my eye than this of so
many thousands of living
creatures in one small drop of
water.”
What can you find in a single
drop of water??
Evolution of Protists
• Evolved from prokaryotes 1.5 billion years ago
• Protists are the first known eukaryotic
organisms
• They would lead to the evolution of fungi,
plants and animals
• A eukaryote that
cannot be classified as
fungi, plant or animal
• An organism that has
very diverse
characteristics
• A microscopic
organism that lives in
water
• Can be grouped into
two general categories:
– Protozoa
– Algae
What is a protist?
How many cells?? (It depends!)
• Most protists are unicellular, but some are
multicellular
• Some are colonial
– each individual has a specific number of cells
– all individuals together make up the colony
– the colony acts like a multi-celled organism
Volvox Colonies
• http://video.google.com/videoplay?docid=3471807967695834419
What is their function? (It depends!)
Some are…
• Producers
– many protists are photosynthetic and are major
contributors to the Earth’s oxygen atmosphere
• Consumers
– some protists eat other organisms for energy
• Decomposers
– some breakdown dead organisms to return
nutrients to the soil
The Protozoa Blues
• http://video.google.com/videoplay?docid=35
78205676570425677&q=protozoa+site%3Avid
eo.google.com&total=13&start=0&num=10&s
o=0&type=search&plindex=2
Protists: The 411
1.
2.
3.
4.
All are Eukaryotes
All are aerobic (require oxygen)
All have mitochondria
All live in water-based environments
(fresh water, oceans and seas, damp soil, snow)
5. Some have chloroplasts
6. Some reproduce asexually, some sexually
3 Main Types
• Plant-like protists
• Animal-like protists
• Fungus-like protists
Plant-like Protists (AKA algae)
• Algae are protists that are
strictly photosynthetic
• Algae are distinguished by the
type of photosynthetic pigment
they contain
• Algae are also classified based
on their cell or body shape
• Most are found in
freshwater
• Major part of
plankton (small
organisms found
on the surface of
a body of water)
• Contain
chloroplasts and
undergo
photosynthesis
Green Algae –
Phylum Chlorophyta
Biscayne Bay – Miami, FL
Brown Algae –
Phylum
Phaeophyta
• Multicellular
• Found in marine and
coastal regions
• Examples: kelp, seaweed
• Can be up to 30 m long
• Provide protection and
shelter for many coastal
fish
Red Algae –
Phylum
Rhodophyta
• Multicellular
• Found in tropical
zones and deep
ocean regions
• Able to absorb
light that
penetrates deep
waters
Caloosahatchee River, SE Florida
(Gulf of Mexico side of Florida)
Diatoms
–
• Unicellular
Phylum
• Cell wall contains silica
Bacillariophyta
(mineral found in glass)
• Double shell (fits
together like the
bottom and top of a
shoe box)
• Their shells are used to
make reflective paints
Dinoflagellates – Phylum Dinoflagellata
• Have 2 flagella
• Huge increases in
population cause red
tides = fish are killed due
to less oxygen in the
water, water looks red
due to overpopulation
• Most are found in
saltwater
Euglenoids – Phylum Euglenophyta
• One flagella
• Eyespot – light sensitive organ that tells the
organism to move toward light
• Found mostly in freshwater
Animal-like Protists (AKA protozoa)
• Classified based on their type of nutrition
• Ingest their food by endocytosis (engulfing
food into the cytoplasm)
Paramecium – Phylum Ciliophora
• Move by beating tiny hair-like structures
called cilia
• The cilia act in unison like oars on a boat
• Have one large contractile vacuole for water
and waste storage
Amoebas –
Phylum Rhizopoda
• Move by
pseudopodia
(false feet)
• Amoebas can live in
water, soil or living
organisms
Sporozoans –
Phylum
Apicomplexa
• All parasites
• Transmitted
through bloodeating insects or
feces
Malaria
• One of the most deadly diseases in humans
• Caused by a protist called plasmodium
• A mosquito bites an individual and the protist is
injected into the blood stream
• Over 100 million people have malaria
• Up to 3 million people, mostly children, die from it
every year
• Symptoms include severe chills, fever,
sweating, and confusion
• Victims typically die of other related
complications including anemia, kidney failure
or brain damage
• Malaria and fake drugs:
http://video.google.com/videoplay?docid=89
97083794746163547&q=malaria&total=1547
&start=0&num=10&so=0&type=search&plind
ex=3 (first 10 minutes)
Fungus-like Protists (AKA molds)
• Two groups
– Plasmodial slime molds
• Phylum Myxomycota
• Look like oozing slime
• Absorb bacteria and nutrients as they slowly move
– Water molds
• Phylum Oomycota
• Usually feed on dead material
• Responsible for the potato famine in Ireland (18451850) that killed almost 1 million people