Phyla #4: Sarcodina
Use PSEUDOPODS to feed and move around
Ex: Ameoba
Ameboid Movement
Use pseudopods to
move and capture prey
Directed cytoplasmic
streaming pushes on the
cell membrane
resembling arms
Ameoba surround
their food with their
pseudopods – a
type of endocytosis
creates a food
vacuole.
phagocytosis
Ameoba reproduce by binary fission
(these are “shelled ameoba”)
Binary fission - ameoba
Other Sarcodinas
1. Heliozoans
2. Radiolarians
Have a shell of silica (SiO2)
Are used in geology for relative
dating of rock strata.
Radiolarians
3. Foraminifers
Have CaCO3 shells that build up on ocean floor
when they die
The Cliffs of Dover are made of foraminifer shells
Parasitic Protists
Plasmodium (causes
Malaria)
Trypanosoma –causes
many diseases including
African Sleeping Sickness
The Tsetse fly –
makes the raising of
cattle impossible in
some regions of
Africa because it
passes on
trypanosoma
Chagas Disease
The only trypanosome native to the Western
Hemisphere
Entamoeba
Causes amebic
dysentery
Consumes food
inside the intestines
Attacks the intestinal
wall – causes
bleeding and
weakens the host
Passed to other
hosts in places were
sanitation is poor
Helpful
Relationships
Ex. Zoomastiginan
Tryconympha
Lives in gut of the
termite and helps
digest cellulose
Has many symbiotic
relationships with
bacteria within IT’S
gut!
Protists are Food
Both marine and
freshwater
ecosystems rely on
the protists for
energy and nutrient
sources
Plant-like Protists
3 phyla
Most contain chlorophyll
and are autotrophic
Considered to be types
of algae (therefore
sometimes classified as
plants)
Phyla #1: Euglenophyta
Phytoflagellates
Closely related to
zooflagellates (really
just zooflagellates
with chloroplasts)
Ex. Euglena 
Euglena movement
Euglena are excellent swimmers using their long
flagellum
When “squished” against a slide, euglena change
shape and “crawl” along the slide – a very “animallike” movement
Euglenoid Movement
Euglena Structure
A red-spot (photoreceptor) helps euglena detect
sunlight so it’s chloroplasts can make glucose using
photosynthesis.
Euglena comparison
Euglena – Autotroph OR
Heterotroph or Saprotroph
If no sunlight is
available, euglena
will eat like other
animal-like protists
Euglena will also
absorb dissolved
nutrients if they are
available, as a
saprotroph will do
Euglena – plant or
animal?
Astasia (a
zooflagellate) and
Euglena are almost
identical – except
that Euglena has
chloroplasts
 Astasia
When Euglena are
grown at 25oC or
more, their
chloroplasts are not
able to reproduce.
After several
generations, the new
Euglena are colorless.
They never regain the
ability to perform
photosynthesis.
(is that where Astasia
came from?)
RRRRRRRRROAR!!
Phyla #2: Pyrrophyta
“dinoflagellates”
Most are
autotrophic, some
heterotrophic
Swim with 2 flagella
– one usually wraps
around the thick
outer plates
Dinoflagellates are
luminescent – they
glow when they are
moved
Phyla #3: Chrysophyta
Includes yellowgreen and
golden-brown
algae, but most
of the species
are DIATOMS.

Diatoms have
intricate shells
made of silicon
(very glasslike)
Diatoms are very abundant in
the oceans
Fungi-like
Protists
(Slime Molds)
1. Acrasiomycota
(cellular slime
molds)
Cellular Slime Molds
Spend most of their
lives as free-living
amoeba-like cells
These cells have a
very high
reproductive rate –
they quickly deplete
the food supply in
the area
When food
runs out, the
amoeboid
cells join
together and
act as a single
organism.
The mass of cells
then act as a
multicellular
organism – it
migrates several
centimeters and
produces fruiting
bodies filled with
spores
The spores are
released and
grow into new
amoeboid cells
It is unclear how
the unicellular
organisms
communicate in
order to migrate
and form the
fruiting bodies
together.
2. Acellular Slime Molds
(Mxyomycota)
Also begin as
amoeboid type
cells
Under stress, the
amoeboid cells
gather together,
and fuse into one
large,
multinucleate cell
called a
PLASMODIUM
The plasmodium produces fruiting bodies
The fruiting bodies
produce HAPLOID
spores
These spores grow
into cells with
flagella
The flagellated
cells swim to each
other and fuse to
create diploid
amoeboid cells
Some
Slime
Molds
Harmful Phytoplankton
Euglenophytes can
act as saprotrophs
and absorb nutrients
from waste
materials and
sewage
If there is too many
nutrients in the
water, the balance is
destroyed, and
phytoplankton can
grow rapidly into
over populated
“BLOOMS”
The “blooms” will
quickly use up all
the nutrients and
then die – and
become waste
material themselves
Red tide is a
caused by a
bloom of a
dinoflagellate
This
dinoflagellate
produces toxins
During a red tide,
it is dangerous to
eat any shell fish
or other filter
feeders
Red tide
Red Tide
Symbiotic Relationships
Many types of
coral house
dinoflagellates
The coral gets
the products of
photosynthesis,
the dinoflagellate
gets a home and
some food
Phytoplankton is
responsible for
more than 70% of
photosynthesis in
the world
This provides a
huge amount of
oxygen and food