Transcript Chapter 5 Protists - Ball State University

Protists
Eukaryotes w/o tissue
level of organization as
in animals, plants, and
fungi
Generalizations
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Most unicellular
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Organelles that are similar to eukaryote
animals
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None have embryonic tissue layers as in
animals
Classification of Protista:
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Excavata
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Diplomonadida = Giardia
Kinetoplastida = trypanosomes
Euglenida = Euglena
Alveolata & Chromista
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Ciliophora = ciliates
Apicomplexa = gregarines, coccidians
Dinoflagellata = flagellates
Opalinida = Opalina
Classification of Protista:
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Rhizaria
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Rhizopoda = amoebas
Actinopoda = radiolarians
Amoebozoa
 Lobosea = amoebas
Opisthokonta
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Chlorophyta = Volvox
Support and Locomotion
Plasma membrane
 Many have thickening = pellicle
 Or a test
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Pseudopodia, cilia, flagella
Nutrition
Autotrophs = ?
 Heterotrophs = ?
 Or both
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Saprobic = take in dissolved stuff
 Holozoic = solid foods (food vacuole)
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Reproduction
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Asexual and sexual
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Complex = parasites
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Binary fission
Budding
Yeast
Sexual repro
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Production of gametes and then fusion =
syngamy
Isogamy = same size gametes
 Anisogamy = one larger
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Or conjugation
Phylum Euglenida
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Mostly freshwater, few marine, brackish
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Usually in habitat w/decaying organic
matter
Support
Pellicle = protein under cell membrane
 Stripes are seams in protein strips
 Flexible
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Locomotion by flagella
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Two flagella, one usually shorter
Nutrition
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1/3 have chloroplasts
Positive phototaxis
 Photoreceptor near base of anterior flagellum
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2/3 euglenids w/o chloroplasts
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= heterotrophs = phagocytosis
Others can lose chloroplasts and switch
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Few parasitic forms
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Saprotrophic = take in dissolved nutrients
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Euglenid reproduction
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Asexual by longitudinal cell division
Euglenida examples you need
to know:
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Euglena
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Perinema
Other Euglenida?
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Phacus
Other Euglenida?
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+ Astasia
Phylum Kinetoplastida
Trypanosomes, etc.
 ~ 600 species described
 Some free-living
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Trypanosomes strictly parasitic
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Digestive tracts of invert’s, phloem of plants,
blood of vert’s
Trypanosoma cruzi life cycle:
Chagas’
Reduviid = assasin bug
Other parasitic forms
Leishmania: transmitted by sandflies
 Causes skin and mucous membrane
infections in humans
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T. gambiense, others = sleeping sickness
Tse-tse fly is intermediate host
 Tryps get into blood, then lymphatics and CS
fluid
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Support, locomotion
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Pellicle, glycoprotein protects outside
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Flagella: single, against side of cell
kinetosome
nucleus
kinetoplast
Nutrition
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Mostly unknown in parasitic forms
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Free-living spp. are heterotrophic; capture
bacteria with flagellum
Reproduction
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Asexual by longitudinal binary fission,
budding
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Complex life cycles
Kinetoplastida you need to
know!
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Leishmania
Infection occurs when infected sandfly regurgitates
infective promastigotes into the blood while feeding.
The promastigotes are phagocytized by macrophages and
transform into amastigotes.
The amastigotes multiply by binary fission in the
macrophages.
The life cycle is continued when a sandfly feeds on an
infected person and ingests the amastigotes in the
macrophages.
Leishmania
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Amastigotes in blood
Leishmania
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Amastigotes in liver cells
Trypanosoma lewisi
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Trypomastigote in vert. blood (infective
form)
Phylum Ciliophora
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~ 12,000 described species
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Common in benthic, planktonic
communities
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Freshwater, marine, brackish
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Most are single celled
Mutualistic symbionts
E.g., in goats, sheep
 Feed on plant material
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Some are parasites in fish gut, one in
human gut
Support, locomotion
Alveolar membrane system
 Underlying fibrous layer = epiplasm
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Cilia in rows; used in taxonomy
More flexible for locomotion than flagella
 Beat in cone
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Ciliophora you need to know:
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Didinium
Ciliophora
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Paramecium, Vorticella
Ciliophora
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Euplotes
Ciliophora
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Spirostomum