Protista
The “Leftovers” Kingdom
1
General Characteristics
All contain a nucleus in each cell
 Most live in watery environments
 Most are single-celled organisms
 Most live as individual cells but many live
as a colony ( a number of relatively
independent cells of the same species that
are attached to one another)

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General Characteristics
Evolved ~ 1.5 billion years ago
 Some are autotrophs, some are
heterotrophs and some can be either
 Three general categories

 Animal-like
 Plant-like
 Fungus-like
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Animal-like Protists


Also called protozoa
(= first animals)
Characteristics of:
 Nucleus
 No
cell wall
 Heterotrophs
 Most can move

4 types:
 Sarcodines
 Ciliates
 Zooflagellates
 Sporozoans
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Sarcodines
Characterized by extensions of the cell
membrane and cytoplasm known as
pseudopods (pseudopod = false foot)
 Pseudopods are used to capture and
engulf particles of food and to move from
one place to another

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Sarcodines

Feed by the process of phagocytosis
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Illustration modified from public domain image http://commons.wikimedia.org/wiki/File:Amoeba_fagocitose.jpg
Sarcodines – with Shells
Many sarcodines have shells (also called
tests)
 The shells must have openings that allow
the pseudopods to extend out
 These shells are part of limestone, marble
and chalk
 Two examples of shelled sarcodines are
foraminiferans and radiolarians

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Sarcodines -Foraminiferans
Although they are unicellular,
these shelled ameboids can be
seen without a microscope.
 They typically are less than
Foraminifera "Star sand"
Hatoma Island – Japan
1mm in diameter, but some
found on the deep ocean floor*,
may reach 20 cm in diameter**.
 Their shells are made of calcium carbonate or
organic materials.

Photo by Psammophile
http://en.wikipedia.org/wiki/File:2085f_Japon
_Hatoma.jpg
FYI: *Commonly found on the Abyssal plains, at depths of up to 6.6 miles.
** Among the largest known unicellular organisms.
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Sarcodines – Foraminiferans
SEM micrographs of four benthic
foraminiferans from the USGS
(Public Domain:
http://en.wikipedia.org/wiki/File:Benthic_foraminifera.jpg )
Tests of foraminifera extracted sand
from the beach of Ngapali (Myanmar)
Photo by: Psammophile
http://en.wikipedia.org/wiki/File:Foraminif%C3%A8res_de_Ngapali.jpg
FYI: Benthic means bottom dweller.
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Sarcodines – Foraminiferans
Live Ammonia tepida benthic
foraminiferan
collected from San Francisco Bay.
Phase-contrast photomicrograph by Scott Fay, UC
Berkeley, 2005.
http://en.wikipedia.org/wiki/File:Ammonia_tepida.jpg
Ammonia beccarii , benthic forams
collected in 2011 on the edge of the
Belgian part of the North Sea.
Photo by: Hans Hillewaert
http://en.wikipedia.org/wiki/File:Ammonia_beccarii.jpg
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Sarcodines - Radiolarians



Radiolarians are
zooplankton that have
a mineral skeleton
containing silica
Their skeletons can
be very elaborate.
They range in size
from 0.1-0.2 mm in
diameter.
Illustration by Ernst Haeckel, 1904, Public Domain
http://en.wikipedia.org/wiki/File:Haeckel_Spumellaria.jpg
FYI: Plankton are organisms that float in the ocean.
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Sarcodines - Radiolarians
Skeleton of a polycystine radiolarian
Public Domain: NASA
http://en.wikipedia.org/wiki/File:Radiolarian.png
Various Radiolaria
Photo by: Luis Fernández García
http://commons.wikimedia.org/wiki/
File:Radiolaria_varios.jpg
REM(Reflection Electron Micrograph) of a Radiolarian
Photo by Hannes Grobe/AWI http://commons.wikimedia.org/wiki/File:Radiolaria_hg.jpg
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Sarcodines – Amebas (or Amoeba)
Reproduce by binary fission (the same as
bacteria) – one cell divides into two
 Respond to light and certain chemicals by
moving away
 Because they live in fresh water they have a
special structure, the contractile vacuole, that
pumps excess water out of the cell. Water
diffuses in by osmosis and must be actively
pumped out or the cell would burst.

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Sarcodines - Ameba
1.
2.
3.
4.
5.
6.
Cytoplasm
Nucleus
Contractile
Vacuole
Cell Membrane
Food Vacuole
Pseudopods
Racette
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Sarcodines - Amebas
Chaos carolinensis
a species of giant ameba (up to 5mm)
Photo by: Dr.Tsukii Yuuji
http://pl.wikipedia.org/wiki/Plik:Chaos_carolinense.jpg
Amoeba proteus
Photo by Cymothoa exigua
http://commons.wikimedia.org/wiki/File:Amoeba_proteus.jpg
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Ameba Videos

Ameba in motion
https://www.youtube.com/watch?v=7pR7TNzJ_pA

Ameba feeding
https://www.youtube.com/watch?v=W6rnhiMxtKU

https://www.youtube.com/watch?v=x1ErCyZCFw8
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Ciliates
All have cilia – small hair-like projections
on the outer surface of the cell
 Cilia do three things


Act like tiny oars to help these organisms
move
 Sweep food particles towards themselves
 Act as tiny sensors
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Ciliates

Have two nuclei
 Large
nucleus (Macronucleus) controls cell
functions
 Small nucleus (Micronucleus) controls the
process of conjugation
Conjugation – two ciliates (same species)
temporarily join and exchange part of their
DNA
 Conjugation is followed by binary fission

Ciliate undergoing binary fission
Photo by TheAlphaWolf
http://en.wikipedia.org/wiki/File:Unk.cilliate.jpg
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Ciliates - Paramecium
Paramecium caudatum
Photo by Deuterostome
http://en.wikipedia.org/wiki/File:Paramecium_caudatum
_Ehrenberg,_1833.jpg
Paramecia, illustrated by Otto Müller, 1773.
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Ciliates - Paramecium




Pellicle – the cell membrane and underlying
structures that give the organism its shape;
without the pellicle a paramecium would look like
a hairy ameba
Gullet – a funnel-like structure that captures food
into food vacuoles
Oral Groove – guides food to the gullet
Anal Pore – empties wastes out of the cell
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Ciliates - Paramecium


Have contractile
vacuoles to pump out
water; look a bit like a
flower
Video:
https://www.youtube.c
om/watch?v=mTXRcb
juYGU
C.V.
Part of a photo by Barfooz
http://commons.wikimedia.org/wiki/File:Para
mecium.jpg
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Ciliates - Paramecium
Illustration modified from Public Domain image http://commons.wikimedia.org/wiki/File:Paramecium_sp.jpg
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Other Ciliates
Blepharisma japonicum
Photo by Frank Fox (www.mikro-foto.de) on
http://en.wikipedia.org/wiki/Blepharisma
Tetrahymena thermophila
Photo Source: Ciliate Genome Sequence Reveals Unique Features
of a Model Eukaryote. Robinson R, PLoS Biology Vol. 4/9/2006,
e304. doi:10.1371/journal.pbio.0040304 (Creative Commons
License)
Vorticella
Photo by Frank Fox (www.mikro-foto.de) at
http://commons.wikimedia.org/wiki/File:Mikrofoto.de-Vorticella_7.jpg
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Other Ciliates - Stentor
A composite image of Stentor roeseli
This work has been released into the public domain by its author, Protist Image Database
http://en.wikipedia.org/wiki/File:Stentor_roeseli_composite_image.jpg
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Zooflagellates

Flagellates are protists that move by
means of a flagellum, a long, whip-like
structure. They may be animal-like, plantlike or fungus-like.

Zooflagellates are animal-like flagellates.
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Zooflagellates
Usually have 1-8 flagella, depending on
the species
 Many live inside the bodies of animals
(they are symbiotic).

are mutualistic – for example those that
live in the gut of the termite and digest wood
 Many are parasitic – Examples include
Typanosoma sp. (causes African Sleeping
Sickness) and Giardia
 Some
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Zooflagellates
Giardia
Public Domain: Centers for Disease Control and Prevention
http://en.wikipedia.org/wiki/File:Giardia_lamblia_SEM_8698_lores.jpg
False color SEM of Trypanosoma
brucei (found in the gut of the
tsetse fly host)
Photo by Zephyris
http://commons.wikimedia.org/wiki/File:TrypanosomaBrucei_Procycli
cTrypomastigote_SEM.jpg
Trypanosoma evansi
Photo by Alan R Walker
http://commons.wikimedia.org/wiki/File:Trypanosoma-evansi.jpg
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Sporozoans
All are parasites that feed on the cells and
body fluids of their host animals
 Many have complex life cycles with more
than one host
 Each forms a spore during some part of
their life cycle that enables it to be passed
from host to host

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Sporozoans - Plasmodium

Several different species of Plasmodium
cause the disease malaria.

They are transmitted only by Anopheles
mosquitos.
FYI: According to the WHO, there were an estimated
207 million cases of malaria in 2012 (uncertainty
range: 135 – 287 million) and an estimated 627 000
deaths (uncertainty range: 473 000 – 789 000).
Ninety percent of all malaria deaths occur in subSaharan Africa, 75% of whom were children under
the age of five.
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Mosquito Photo Credit: James Gathany, CDC
http://en.wikipedia.org/wiki/File:Anopheles_albimanus_mosquito.jpg
Plasmodium Life Cycle
Each sporozoan divides
to form many spores
Sporozoans
develop in the
mosquito’s gut
Mosquito bites
human and
drinks infected
blood
Spores move to the
mosquito’s mouth
Female Anopheles albimanus mosquito,
transmits malaria in Central America
In Mosquito Host
In Human Host
Red blood cells burst
releasing sporozoans
that then infect more
RBCs
Liver and Blood cell diagrams part of Public Domain image from NIH
http://sw.wikipedia.org/wiki/Picha:MalariacycleBig.jpg
Mosquito bites
human injecting
spores
Spores travel
to the liver
Infect liver cells,
multiply and
burst out
Sporozoans infect red
blood cell and multiply
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