Protists Are Not…
Name: _______________________________ Pd:_____
Kingdom Protista
Protists may be single-celled or many-celled organisms or can live in groups called colonies. They
contain membrane-bound organelles, including an organized nucleus—they are eukaryotic. Most live in
water environments, but a few species live in very moist areas on the land or inside other organisms.
Some Protozoans do not move at all, but many of them are able to move. Some protists use
psuedpods, or false feet to change its shape and move. Other protists move using tiny, hair-like structures
called cilia. The cilia are found on the outside of the cell. They are able to move very quickly back and
forth, moving the protists along through water or another liquid. Finally, some protists move using flagella.
These are simple, whip-like structures that propel the protist through its environment.
Most protists reproduce asexually with binary fission but some can reproduce sexually by a process
called conjugation. In conjugation, two protists attach to each other and exchange genetic material.
Scientists believe that protists evolved originally from the bacteria, but understanding their history is
difficult because most lack hard parts (like bones or shells) so there is very little fossil evidence. It is thought
that mutations over time have made the structures of the protists more complex than the bacteria.
Plant-like Protists
Plant-like protists are called algae. Algae are producers, containing chlorophyll in chloroplasts and
making their own food (autotrophic). Algae may contain other pigments (colors) as well as chlorophyll,
giving them a color other than green. (The chlorophyll is there, it is just “overpowered” by the other color.)
Almost all algae live in water. Phytoplankton, single-celled algae that float near the surface of the water,
are an important part of the food chain and release a lot of oxygen into the atmosphere.
Algae are grouped into 6 different phyla based on their color.
1. Golden Algae—Phylum Chrysophyta
Diatoms are a marine (saltwater) species of golden brown algae that make up much of phytoplankton.
2. Fire Algae—Phylum Pyrrophyta
Dinoflagellates are single-celled marine organisms that have a red pigment, usually with 2 flagella that work
together to produce a spinning motion.
3. Green Algae—Phylum Chlorophyta
This type of algae can be single or many-celled or may live in colonies (example: Volvox). They live mainly
in water environments, but can also live in soil and on trunks of trees (if the area is moist).
4. Red Algae—Phylum Rhodophyta
Most are many-celled and live in marine environments (ex. some types of seaweed).
5. Brown Algae—Phylum Phaeophyta
These many-celled organisms live in marine environments. Many forms of seaweed are species of brown
algae (ex. kelp). Brown algae are important sources of food and shelter for marine animals.
6. Euglena—Phylum Euglenophyta
Euglena are single-celled organisms that have characteristics of both plant and animals.
Protists Are Not…
Name: _______________________________ Pd:_____
Animal-like Protists
Single-celled, animal-like protists are known as protozoa (singular: protozoan). Protozoa can live in water
environments and in soil. They are heterotrophs and can eat by capturing living organisms, feeding on
dead things (saprophytes), or as a parasite in another living organism (in a host).
Protozoans are divided into four phyla based upon their method of movement.
1. Sarcodines—Phylum Sarcodina
Sarcodines are found mostly in fresh and saltwater environments, but can also live in hosts as parasites.
Sarcodines move by using pseudopods (ex. amoeba are typical sarcodines).
2. Flagellates—Phylum Mastigophora
Most flagellates live in fresh water but can be parasites, causing disease (ex. Giardia which affects the
intestines.) They all have one or more flagella that whip back and forth to help them swim in the water.
3. Ciliates—Phylum Ciliophora
Most ciliates live in water environment, and because of their cilia will appear to move in smooth, straight
lines.
4. Sporozoans—Phylum Sporozoa
Sporozoans live only as parasites. They live in and feed on the blood of their hosts. Plasmodium is the
sporozoan that causes malaria. It is spread by one species of mosquito.
Some Interesting Creatures found in Kingdom Protista
The Kingdom Protista contains both single celled and multi-celled organisms. They are VERY small – most
cannot be seen without a microscope. They live in aquatic habitats (water) and most eat bacteria, other
small organisms or particles they find in the water with them.
In today’s lab, you will be viewing three different water specimens. Use the following pages when you are
viewing your pond water specimens as guides for identifying the organisms you are seeing. You will
probably not find all of these protists in your pond water, but take a close look at your slide – you may see
some of the organisms described in this guide. Be careful - these amazing little creatures are often quite fast
and may swim right out of sight!
DINOFLAGELLATES: Dinoflagellates are a type of
algae that can make their own food like plants. They
move with little whips called flagella that they swing like
propellers through the water. They have hard cell walls
like armor surrounding their body. Sometimes the
number of these creatures becomes so great in the ocean
that it makes animals in the water (like fish and people)
very sick. This is called “red tide” because the brownish
dinoflagellates turn the water red.
Protists Are Not…
Name: _______________________________ Pd:_____
AMOEBAS: The amoeba is a protozoan and an animal-like protist. Amoebas are oddly shaped protists
that move by extending parts of their body as little feet (pseudopods) and then pulling the rest of the body
behind. The amoeba stretches its cytoplasm to create the pseudopods ("false foot"). The amoeba can
completely change its shape. They eat by surrounding a piece of food with their pseudopods and then
taking it into the inside of their bodies, in a
food vacuole, where it is slowly digested.
Note the round food vacuoles inside of
the amoeba in the diagram. Because it can
move and it consumes its food (consumer)
it is a heterotroph. Amoebas live in ponds
or puddles, and can even live inside
people. These amoebas are parasites that
can live in larger animals (like us!) and
make them very sick. One disease caused
by the amoeba is called Amoebic
Dysentery. A person becomes infected by
drinking unsanitary water. The amoeba
upsets the person's digestive system and
causes cramps and diarrhea.
EUGLENAS: Euglena is a single celled (unicellular) organism. Euglena lives in ponds or puddles. They
are protists that move with little whips called flagella that they swing like propellers through the water. The
flagellum is located on the front end, and
twirls in such a way as to pull the cell
through the water. Some are green, like
plants because they contain chlorophyll in
chloroplasts. When light is present, they
can make their own food (producers,
autotrophs). Euglena has an eyespot at the
front end which detects light. This helps
the Euglena find bright areas to gather
sunlight to make their food. When light is
not available, they can capture and use
other organisms as food sources. Like
animals, they have a way to move (their
flagellum) and a way of sensing their
environment (their eyespot). The Euglena
has a stiff pellicle outside the cell
membrane which helps it keep its shape.
Toward the back of the cell is a star-like
structure called the contractile vacuole
which helps remove excess water.
Protists Are Not…
Name: _______________________________ Pd:_____
EUPLOTES: Euplotes are protists which have
tendril like structures called cirri, which function a
bit like little “legs” that they use to swim or even
“walk” on things. The four long cirri often project
at different angles making them hard to see at the
same time without a change of focus when viewed
through a microscope. They also have some tiny
“hairs” called cilia that they wave to bring food into
their bodies by making a small current.
PARAMECIUM: Paramecium is a one-celled (unicellular) protozoan. They live in quiet or stagnant ponds.
Paramecia are consumers. Like euplotes, the paramecium sweeps food (usually bacteria, algal scum, smaller
protists, or other microorganisms) into its “mouth,” an oral groove with an opening into the paramecium.
Food enters the paramecium through the mouth pore and
goes to the gullet. At the end of the gullet, food vacuoles are
formed. Food vacuoles remain in the cytoplasm until the food
is digested. Undigested food particles are eliminated through
the anal pore. The paramecium can shoot tiny threads out of
the cell to entangle a predator or to make themselves appear
bigger. Small organisms also eat them. The paramecium is
entirely covered in little “hairs” called cilia that it waves in
order to swim through the water. The star-shaped contractile
vacuole contracts to force out excess water from the
Paramecium. A Paramecium also has two types of nuclei: the
macronucleus controls everyday activities such as respiration,
protein synthesis and digestion, and the micronucleus controls
reproduction. Unlike the amoeba, the paramecium cannot
change its shape because, like the euglena, it has a stiff thick
outer membrane called the pellicle.
CHILOMONAS: These small, colorless protists also move by means of
flagella. They are a favorite snack of amoebae and other larger protists!
Protists Are Not…
Name: _______________________________ Pd:_____
STENTOR: These protists either swim freely (shaped like
pears) or attach themselves to particles where they look like
the picture to the right. They move mainly with cilia.
When attached, the stentor eats by creating a big funnel as
shown above. It uses its cilia to create a whirlpool that
sucks the food down its “mouth” (think of a flushing
toilet!)
VOLVOX: These protists are actually individual cells of algae that
have formed a spherical (round) colony. Each volvox colony can
contain over 500 cells that cling to the hollow ball of mucilage.
Amazingly, each cell has flagella that will whip in the same direction
as others to propel the volvox through the water! The balls you see
inside of the volvox are actually daughter colonies that have formed
from one cell inside of the colony. Volvox can reproduce both
sexually and asexually. Eventually when the mother colony breaks
apart the daughters will become their own free colonies.
DIATOMS: This group of protists is
called the golden algae. They contain
chlorophyll in chloroplasts and use energy
from the sun to make their own food.
They live in marine environments.
Diatoms form a hard, box-like shell around
their cells. These do not decompose, but
instead sink to the ocean floor and collect
in layers. These shells are used
commercially for many applications
including grit in toothpaste, cosmetics,
water filters, highway paints, and scouring powders.
Protists Are Not…
Name: _______________________________ Pd:_____
Be on the lookout for imposters!
ROTIFERS: These creatures are NOT protists but are
actually animals like us. They are found in Phylum
Rotifera.
Though they have many cells, they can be smaller than
some of the one-celled protists! There are many different
types that have interesting ways of moving. Several types
are pictured in the diagram.
CYANOBACTERIA: These creatures are NOT protists but are actually bacteria. Because they obtain
their energy through photosynthesis they used to be called blue-green algae, but this name is not correct
because they are prokaryotic organisms.
Protists Are Not…
Name: _______________________________ Pd:_____
Answer the following:
1. How does an amoeba move?
2. To what Kingdom does the amoeba belong?
3. What disease is caused by the amoeba?
4. Are Euglena unicellular or multicellular?
5. What organelle carries out photosynthesis in the Euglena?
6. What is the purpose of the eyespot in the Euglena?
7. What would happen if the Euglena cell did not have the contractile vacuole?
8. Is the paramecium a unicellular or multicellular organism?
9. What does a paramecium eat?
10. Where do paramecia live?
11. When I look at one of the organisms in the microscope, I notice a tiny nucleus inside the cell. This
organism should be classified in which kingdom?
12. This organism is moving. I notice that it is a single cell, with a flagellum. I cannot tell if this
organism has a nucleus or not. This organism should be classified in which kingdom?
13. I collected this sample from the ocean. This small cutting which has a brown tint is from an
organism which was about 27 meters tall. I notice that it is made up of many cells. What phylum
might this organism belong to?
14. This organism is moving. I notice that it is a very small single cell, with a nucleus and two flagella.
As I am watching, it is eaten by an amoeba! What organism might this be?
15. This organism is moving, and as I watch it eats another organism. I notice that it is small but still
multicellular. It seems to be shaped like a tiny flea. What phylum might this organism belong to?
16. This organism is is a single cell, and seems almost crystalline. I notice a golden color, and identify
something I believe is a chloroplast. What phylum might this organism belong to?
17. When I look at the next organism, I notice it has more than one cell. I don’t see any tissues or
organs, but the group of cells seems to be a ball shaped colony. What protist might this organism be?
Protists Are Not…
Name: _______________________________ Pd:_____
18. Choose two of the organisms listed in this guide, and compare them using a Venn diagram.
Using the samples provided, answer the following:
19. Identify an organism. Describe what
you see. ______________________
______________________________
______________________________
______________________________
______________________________
______________________________
Possible identification:
______________________________
20. Identify an organism. Describe what
you see. ______________________
______________________________
______________________________
______________________________
______________________________
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Possible identification:
______________________________