Protists are unicellular organisms that have a nucleus.
Kingdom: Protista
Similar to Bacteria

Unicellular

One of the first groups of living things on Earth.
(1.5 billion years ago.)

Microscopic

Can cause disease.

Can be parasites
Difference from Bacteria

Has a nucleus.

Live in watery environment.

Generally live as individual cells.

Protists vary greatly in appearance and function.
3 Categories

I. Animal-like Protists.

II. Plant-like Protists.

III. Fungus-like Protists.
I. Animal-like Protists

Protozoan means “First Animal”.

Cells contain a nucleus.

Cells lack a cell wall.

They are heterotrophs.

Most can move on their own.
4 Groups of Animal-like
Protists

1. Sarcodines (SAHR-koh-dighnz)

2. Ciliates (SIHL-ee-ihts)

3. Flagellates (FLAJ- ehl-ihts)

4. Sporozoans (spohr-oh-ZOH-uhnz)
1. Sarcodines

Have pseudopods (Greek:“false foot”)

Extensions of the cell membrane and cytoplasm.

Pseudopods are used for movement and to capture
food.

Many have shells.

These shells form limestone, marble and chalk.
One type:

Most familiar
Sarcodine.

Pseudopods:

Blob shaped.

Contractile Vacuoles:
controls amount of
water inside

Food Vacuole: where
food is digested.
Split Personality

Amebas reproduce by
dividing into two new
cells (binary fission).

Amebas can respond
to their environment.

They are sensitive to
light and some
chemicals.
2. Ciliates

Have cilia on the
outside of their cells.

Tiny hair-like
projections used for
movement, to gather
food and as feelers.

Pellicle: tough outer
wall.

Slipper shaped

Oral groove: like the
mouth

Gullet: holds food.

Food Vacuole: digests
food.

Anal Pore: removes
wastes

2 Contractile Vacuoles

2 Nuclei

Reproduces by either
binary fission or
conjugation.
Type: Paramecium
3. Flagellates
(Zooflagellates)

Have a Flagellum: a
long whip-like structure
used for movement.

Many live in animals

Symbiosis a close
relationship, at least
one benefits.

Mutualism: when both
partners benefit.
4. Sporozoans

All Sporozans are parasites.

They feed on cells and body fluids.

Form from Spores (tiny reproductive cells).

Pass from one host to another.

Pass from ticks, mosquitoes or other animals to
humans.
II. Plant-like Protists
(Algae)

Unicellular and Multicellular

Colonies (groups of unicellular protists)

Can move on their own

Autotrophs: make their own food from simple materials using light
energy (photosynthesis).

70% of the Earth’s oxygen is produced by Plant-like Protists!

Pigments: chemicals that produce color
6 Groups of Plant like
Protists

Euglenoids (yoo-GLEE-noydz)

Diatoms (DIGH-ah-tahmz)

Dinoflagellates (digh-noh-FLAJ-eh-layts)

Red Algae

Green Algae

Brown Algae
1. Euglenoids

Green

Unicellular

Live in fresh water

Autotrophs, but can be
heterotrophs under certain
conditions.

Flagella

Eyespot: sensitive to light.

Chloroplasts

Pellicle
2. Diatoms

Unicellular

10,000 living species.

Aquatic

Glass like cell wall

Diatomaceous earth:
course powder that
comes from dead
diatoms (toothpaste,
car polish & reflective
paint.
3. Dinoflagellates

Unicellular

Cell walls are like
plates of armor.

Two flagella

Spins when it moves.

Colorful (pigments)

Can glow in the dark.

Causes Red Tide
Red Algae

Multicellular seaweeds

Live in deep ocean waters

Used for ice cream and hair
conditioner

Used as food in Asia
Green Algae

Most are unicellular

Some form colonies

Few are multicellular

Can live in fresh and salt water
and on land in damp places.

Very closely related to green
plants.
Brown Algae

Commonly called seaweed

Can contain brown, green,
yellow, orange and black
pigments.

Attach to rocks

Have air bladders

Giant Kelp can be 100 meters
long!

Used as food thickeners
III. Fungus-like Protists

Heterotrophs

Have cell walls.

Many have flagella and are able to move at some point in their lives.

Three types: Slime Molds, Water & Downy Molds

Reproduce with Spores (tiny cell that is able to grow into a new
organism)
Water & Downy Molds

Live in water or moist places.

Tiny threads that look like fuzz.

Attack food crops

Caused the Irish Potato Famine.
Type:

Reproduce by Fruiting
Bodies:

The Fruiting Bodies
contain Spores.

At first they look like
ameba, then later they
look like mold.

Live on moist shady
places.

Feed on bacteria and
other microorganisms.