Transcript Kingdom Protista

Protists
Domain Eukarya
Kingdom Protista
Microscopic
Critters Abound!
Characteristics of Kingdom Protista
• Heterogeneous assemblage of unicellular,
colonial and multicellular Eukaryotes
that do not have the distinctive
characters of plants, animals or fungi
• Contains a number of organisms previously
classified as plants, animals or fungi.
• Classification based on movement and
pigment (our text)
• Cells typically 1 μm to 50 μm, up to 60
meters (seaweed)
Importance
• Important components of food chains. E.g.
kelp beds are among the most
productive ecosystems on earth
• Unicellular aquatic Protista (plankton)
form an important component of the
food chain. The photosynthetic ones are
called phytoplankton and the
heterotrophic ones are called
zooplankton (which also includes
many animal larvae or tiny crustaceans)
Motility
Motility – the ability to move spontaneously and
independently
Some are motile, some are NOT motile
Some move using:
 cilia
 flagella
 streaming (amoeba use “arms" called a
pseudopod)
Domain Eucarya
Kingdom Protista
Phylum Sarcodina
Phylum Sarcodina
• Unicellular
• Move by pseudopodia
• Some surrounded by a calcium "shell"
• Amoeba has no definite shape
• Shape is constantly changing
• Food is surrounded by pseudopods and
stored in a food vacuole
Amoeba proteus
Sarcodina Reproduction
• Asexual–only known method!
Phylum Ciliaphora
• Unicellular
• Nuclear dimorphism : two functionally
distinct kinds of nucleii
• Micronucleus is specialized for sexual
exchange
• Macronucleus is specialized for
transcription
Paramecium Anatomy
Paramecium Reproduction
• Asexual – binary fission
• Sexual - conjugation
Under certain conditions, such as overcrowding or
environmental stress, Paramecium
turns from strictly asexual reproduction
to sexual reproduction. Sexual
reproduction involves the exchange of
genetic material between two
individuals of different 'mating strains'.
Involves meiosis.
Reproductive Cycle
And now for a
pleasant
review of
mitosis and
meiosis!
Phylum Zoomastigina
The Flagellates
• Move by flagellum or flagella
• Other zooflagellates may live inside as
parasites
• Some diseases caused by flagellates are
transmitted by insects
• Can become infected by contaminated
water
• Some live in the digestive tracts of
termites and assist in the digestion of
cellulose.
Pathogenic examples of Zooflagellates
• Giardia lamblia – “Hiker’s disease”
• Trypanosoma cruzi
• Transmitted by insects-Reduviid insect
• Causes Chagas’ disease
Mainly in Latin America:
18 million are infected each
year; 50,000 die yearly.
Affects major organs:
Heart
Liver
G.I. tract
Brain
http://www.cdc.gov/ncidod/dpd/parasites/chagasdisease/factsht_chagas_disease.htm
• Vector - <L. vehere to carry
• Metacyclic – infective stage
• Trypomastigotes flagelatted form of
parasite that lives in the blood.
• Amastigotes or mastigotes Unflagelatted form that lives in cells
Phylum Sporozoa
Plasmodium
• Unicellular
• All Parasitic!
• Responsible for malaria
• Move by gliding motion in some stages
Plasmodium Lifecycle
Domain Eucarya
The Algae
Kingdom Protista
Benefits of Algae
 All algae provide food for microorganisms which larger
animals and fish can eat
 Surface and hair algae provide food for fish directly
 All algae absorb excess pond nutrients like ammonia,
nitrate, and phosphate
 Suspended algae provides some shade to pond
animals and plants in the spring
 All algae provide oxygen during the day (but use it at
night)
 Hair algae provides a soft spawning site for fish.
Algae Classification
Phylum Euglenaphyta
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800 to 1000 species
Photosynthetic when light available
Heterotrophic when light unavailable
Resemble protozoans due to flagella
Freshwater and brackish water
inhabitants
Euglenaphyta
Euglena
Euglena Reproduction
Binary Fission
Euglena rubra
E. sanguinea This is due to
the pigment called astaxanthin
Phylum Chlorophyta
 7,000 species
 Most freshwater, but some terrestrial; a
few marine
 Contain chlorophylls a, b, and
carotenoids
 Unicellular, colonial, and multicellular
 Spirogyra
 Hair algae
Phylum Chrysophyta
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850 species
Store food as oils
Most unicellular, some colonial
Cell walls made of cellulose
Chrysophyta
 Vaucheria
Phylum Bacillariophyta
 1150 species
 Supply more oxygen than all other
organisms
 Store food as oil
 Silica walls contain silica used for filters,
insulate boilers, abrasive factor in
toothpaste
Bacillariophyta
 Diatoms
Phylum Phaeophyta
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All multicellular
Almost all marine
Brown algae
Contain chlorophyll a, c, and fucozanthin
Provides algin – thickener in cheap ice
cream
 Stem-like structure has air bladders that
allow it to float near surface of water
Phaeophyta
 Fucus
Phylum Rhodophyta
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Mostly marine
Multicellular
Color derived from phycobilins
Less than 30 cm long
Important in building reefs from calcium
deposition
 Products: agar, gelatin shells of drug
capsules
Rhodophyta
 Gelidium pulchrum
Phylum Dinoflagellata
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Unicellular
Possess two flagella
Cell walls composed of cellulose
Mostly marine
Some bioluminescent
Responsible for red tides!
Dinoflagellates
Ceratium sp.
Protoperidinium sp.
RED TIDE!
Disadvantages of Algae
 Suspended algae reduces clarity so that
animals and plants cannot be seen in the pond
 All algae reduce oxygen levels at night
 All algae may cause pH fluctuations
 All algae may cause the death of submerged
plants, water lilies, etc. due to either reduced
light levels or strangulation in the case of hair
algae
 Hair algae can clog filters, pumps, etc
 Finally, many people find algae ugly
Eutrophication
Can occur naturally or induced