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The Protists!
Fungi – ecological
significance,
mycorrhizae!
Protista –
multicellular
defined by
absence of
characteristics!
Animalia –
animals,
metazoa !
Plantae –
chlorophyll a
and b, conifers,
mosses, ferns,
flowering plants !
Archae – unicellular, extreme habitats! Eubacteria- unicellular, range of environments!
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Emergence of the !
Eukaryotes!
!
Proposes that certain prokaryotes were
incorporated into a larger species of
prokaryote = prey or parasites!
!
Chloroplasts = photosynthesizing
cyanobacteria!
!
Mitochondria = aerobic heterotrophs!
!
!
!
Host and endosymbiont became
interdependent to form a single organism!
The Protists!
-  Many single celled members of the kingdom Protista!
-  Clearly eukaryotes = distinct nuclei, membrane bound
organelles!
-  Remarkably diverse in terms of size, morphology, nutrition,
locomotion and reproduction!
!
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Protists can be – !unicellular, colonial, multicellular!
Paramecium!
Volvox!
Euglena!
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General Protozoan Characteristics!
Entire organism is enclosed in
the cell membrane = naked or
armored, different composition!
!
Cytoplasms = clear outer
ectoplasm and less
transparent, fluid region or
endoplasm!
!
Organelles typical of most
multicellular metazoan cells !
!
Many protozoan protists
contain organelles not found
among metazoa, e.g.
contractile vacuoles,
trichocysts!
Locomotory Appendages!
Cilia – microtubular construction, coordinated!
ciliary beat, generally many = brush border !
https://www.youtube.com/watch?v=RakqKYHenxU!
!
Flagella – same construction, but different number and size
(length), different pattern of movement!
https://www.youtube.com/watch?v=jl0TzaWUQWk!
!
Podia – extensions of the cytoplasm created by cytoplasmic
streaming!
!
!
!
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PLANKTON!
Euglenida:!
Euglena, Phacus, Trachelomonas!
aqueous environment = marine or freshwater, free!
!
flagellar movement typically of the members of the
phylum formerly known as Sarcomastigophora!
!
very mobile (examine live specimens in lab) = due to a
pellicle rather than cell wall!
!
mixotrophic = poor environmental conditions may
result in change from autotrophic to heterotrophic
and vice versa!
!
eyespot = positively phototactic = when mobile and
autotrophic you need to be able to move actively
towards light!
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Flagellae = often referred
to as single!
Reproduction = asexual!
absorption of flagellum!
formation of microtubules!
= below pellicle!
mitosis!
= creation of immature
zoospores!
zoospores break apart, grow!
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Kinetoplastida:!
Trypanosoma, Leishmania, Rhyncomonas!
also formerly belonging into Sarcomastigophora!
symbiotic and includes pathogenic parasites = African sleeping
sickness!
affect different vertebrates, !
including humans!
!
!
!
!
!
!
flagellum attached to mitochondrion (kinetoplast) via undulating
membrane = energy support for movement!
transmitted through bite of Tsetse fly!
Asexual = binary fission, sexual = nuclear fusion!
Ciliophora:!
Paramecium, Didinium, Tetrahymena!
probably the most complex of unicellular
organisms!
!
!
diverse protist group, is named for their use
of cilia!
!
Macro & micronucleus, vacuoles (digestive,
contractile), cytostome vs cytoproct,
extrusosomes!
!
Mostly freshwater, few parasites (1 causing
human disease)!
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Feed on algae or other
ciliates!
Cyst formation = dry
periods!
Reproduction !
= asexual by division!
= sexual by conjugation, cytoplasmic !
bridge, macronuclei disintegrate, micronuclei exchange,
formation of new macronuclei!
Dinoflagellata !
Dinophyta, Pyrrophyta (Gr. dinos: whirling; L.
flagellum: whip) (= Pyrrophyta) (Gr. pyros: fire, and
phyton: plant) !
– refers to bioluminescence of many forms!
- most are biflagellated, unicellular!
- may be unarmored (naked) or armored (thecate,
pellicle)
! !!
Dinophysis!
Ceratium!
Noctiluca!
Gymnodium)
Peridinium!
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Rhizopoda!
Amoeba, Entamoeba, (Chaos)!
aqueous = freshwater and
marine, well watered soils!
!
mostly free-living
heterotrophs !
!
pseudopodia = extensions!
!
parasites = Entamoeba
histolytica = amoeboid
dysentery!
!
reproduction by binary
fission!
Actinopoda!
Actinosphaerium, Radiolarians!
marine, siliceous skeleton!
= bubbly appearance!
!
related to what used to be
Zoomastigophora!
!
axopodia = very thin
spicule like cytoplasmic
extensions, generally not
involved in locomotion!
!
reproduction = asexual,
binary fission!
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Parabasilida:!
Trichonympha, Trichomonas!
generally symbiotic in higher
organisms!
= help them digest cellulose!
!
flagellated = between 4-thousands!
!
anaerobic = lack mitochondria!
!
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