Kingdom Protista
BIOLOGY 11
2 million people a year…because of a protist!
3000 Kids a day!
Introduction to Protists
 Protists (from the Greek first) are the first kingdom
of unicellular, eukaryotic organisms (cells contain a
nucleus and membrane bound organelles).
 They are approximately 1.5 billion years old
indicating that the evolution of the first protist took
approximately 2 billion years (the oldest fossil of a
moneran is 3.5 billion years).
How did Protists come to be???
 There is a strong resemblance between several of the
organelles (mitochondria and chloroplasts) and
cyanobacteria and bacteria.
 The cilia and flagellum found in eukaryotic cells are
similar to a group of bacteria referred to as spirochetes.
 One hypothesis is that the previous prokaryotes lived
with another moneran in a symbiotic relationship.
 This hypothesis is called the Endosymbiont
Hypothesis
The Endosymbiont Hypothesis
How Kingdom Protista is broken down…
KINGDOM PROTISTA
Animal Like
Plant Like
Fungus Like
Protists
Protists
Protists
Phylum Ciliophora Phylum
Phylum
Euglenophyta
Acrasiomycota
Phylum
Zoomastigina
Phylum Pyrrophyta
Phylum Sporozoa
Phylum Sarcodina
Phylum
Chrysophyta
Phylum
Myxomycota
Animal like Protists- Phylum Ciliophora
#1-Phylum Ciliophora-Cilia bearing protists
 Cilia – hair like projections, composed of
microtubules, that are able to move and propel the
organism through water.
 Ciliophora – approximately 7000
members are either solitary or live in
colonies and are known as ciliates
Animal like Protists- Phylum Ciliophora
 Paramecium (Example of Phylum Ciliophora)
 Large single celled organism that contains two different
kinds of nuclei – a macronucleus and a micronucleus
 Obtains food by using its cilia to force water into an
indentation in one side of the cell called a gullet. The
food is forced into cavities called food vacuoles that break
off into the cytoplasm and fuse with lysosomes that
contain digestive enzymes
 Waste materials are emptied into the environment when
the food vacuole fuses with the anal pore.
Animal like Protists- Phylum Ciliophora
Paramecium cont’d
 Because water is constantly entering the
paramecium due to osmosis there are contractile
vacuoles that once filled with water, contract and
pump water back out.
 Reproduce asexually through binary fission
Single paramecium elongates, splits its gullet in two, and the cell
divides crosswise giving two identical cells.
 Under stressful conditions (starvation and changes in
temperature) paramecia will undergo sexual reproduction in a
process called conjugation

Paramecium Life Cycle
Paramecium Conjugation
 Macronuceli disintegrate and their diploid micronuclei
undergo meiosis so that by the end each paramecia have 4
haploid micronuclei
 3 of the 4 micronuclei disintegrate and the 1 remaining one
divides to form 2 identical haploid micronuclei
 The paramecia exchange one micronucleus so that each cell
has one micronuclei obtained from the other paramecium
 Paramecia separate and the 2 haploid micronuclei in each
paramecium fuse to form a new diploid micronucleus. From
the micronucleus a new macronucleus is formed.
Phylum Zoomastigina
#2 Phylum Zoomastigina – Animal like Protista with
Flagella
 Move through the water by means of 1 – 4 flagella
 Generally able to absorb food through cell walls and live
in environments that have enough food for them to
absorb. Some live in other organisms to utilize the
nutrients that the other organism consumes.
 They reproduce mainly through asexual reproduction but
are able to produce gamete cells through meiosis which
fuse together forming an organism with a new set of
genetic information.
Phylum Zoomastigina
 With the lack of a cell wall, nutrients are able to be
passively absorbed into the protist. They live in
environments in which there is plenty of nutrients –
lakes, ponds or as parasites of other organisms
 Typically when organisms are stressed – through
change in temperature, oxygen levels, or nutrient
levels, they need to find ways to ensure that they can
survive – as a result they produce gamete cells
through meiosis which fuse to “create a new
combination of genetic information.
Phylum Sporozoa
#3 Phylum Sporozoa – spore producing parasitic protists.
 Non motile parasites that infect worms, insects, fish, birds,
and humans
 Complex life cycles that involve more than one host.
 Reproduce by means of cells that are enclosed in a protective
membrane (spore)
 Spores attach to a host cell, penetrate it, and then live within
it as a parasite.
 Eg.- Plasmodium – causes malaria
How does Malaria work?
Phylum Sarcodina
#4 Phylum Sarcodina – Protists
with false feet
 Amoebas – flexible active cells
without cell walls, flagella, cilia, and
even a definite shape. They move by
extending the pseudopod and then
the cytoplasm stream into it. It eats
in a similar manner in which it
extends its cytoplasm over its food
and then ingesting it to form a food
vacuole.
Phylum Sarcodina
 Reproduce through binary fission – one large ameba
divides by mitosis to produce two smaller but
genetically identical amoebas.
 Also contain three groups known as heliozoans,
radiolarians, and foraminifers
 These organisms create delicate
shells in a variety of ways.
Plant Like Protists
#1 Phylum Euglenophyta – Flagellates with
Chloroplasts
 Closely related to Zoomastiginans
 Most common member is Euglena
 Long cell which has two flagella that it uses to propel it
forward through water
 Able to move by changing its shape so that it can “crawl”
along a surface. This movement is very animal like in
appearance
Phylum Euglenophyta
Has an eyespot at the end with the flagella that it uses to
find bright light as it is filled with between 10 to 20
chloroplasts
 If there is no sunlight available it can also absorb
nutrients that are in the water around it (these organisms
that can absorb decayed organic nutrients are referred to
as saprophytes)

Phylum Euglenophyta

The pellicle (cell membrane and associated structures) is
unusual because it consists of a series of ribbon like
ridges that spiral around the surface of the organism.
Underneath each ridge is a small sac and microtubules
that are thought to be responsible for maintaining the
cells shape and its euglenoid movement.

Reproduces asexually by binary fission. Just before
division the cell doubles the number of ridges by placing
them between existing ones. It starts division at the ends
with the flagella.
Phylum Pyrrophyta
#2 Phylum Pyrrophyta – Fire Protists
 Group of organisms known as dinoflagellates most of
which are photosynthetic (though some have lost their
chloroplasts and are heterotrophs
 Usually swim using two flagella one of which wraps
around the organism like a belt and the other trails
behind like a tail
 Many are covered in thick plates that give them an
armored appearance
Phylum Pyrrophyta
 Reproduce asexually through binary fission
 Luminescent and will give off light with sudden
movement
 Unlike all other eukaryotes, dinoflagellates do not
have their DNA bound with special proteins called
histones.
Phylym Chrysophyta
#3 Phylum Chrysophyta:
Golden Protists
 Three organism in this phylum –
yellow-green algae, golden-brown
algae, and diatoms.
 Contain one or two gold-green
chloroplasts
 Cell walls contain the
carbohydrate pectin instead of
cellulose and store food as oil
instead of starch.
Phylym Chrysophyta
 Some have flagella
 Reproduce both sexually and asexually and although
usually solitary, they can live in threadlike colonies
 All but about 2000 of the
species in this phylum
belong to the diatoms
Phylym Chrysophyta
 Diatoms
 Cells that produce cell walls
rich in silicon which is the
main ingredient in glass.
 Cell walls are like the two sides
of a petri dish so that one side
fits snuggly into the one beside
it
 Photosynthetic and most
abundant species in the ocean.
Fungus like Protists- Phylum Arasiomycota
#1 Phylum Acrasiomycota
 These slime molds are cellular
 They begin their life cycle as individual cells and they
look amoeba like
 When they need food the free living cells gather to
form a reproductive fruiting body
Examples of different slime molds
Phylum Myxomycota
#2 Phylum Myxomycota
 These slime molds are acellular
 They begin their life cycle like Acrasiomycota, but
these slime molds produce a structure called
plasmodia
 Unlike Arasoimycota, Myxomycota is a single
multinucleate cell