The Protist Kingdom …And the 3 “Classic” Protists!

The Protist KingdomThe Protist Kingdom

……And the 3 “Classic” Protists!And the 3 “Classic” Protists!

What is a Protist?What is a Protist?

ProtistsProtists: Eukaryotic organisms that : Eukaryotic organisms that cannot be classified as animals, plants, or cannot be classified as animals, plants, or fungi.fungi.

Protists are very varied, but they do have Protists are very varied, but they do have some similarities. Beside the fact that they some similarities. Beside the fact that they are are all eukaryoticall eukaryotic, they , they all live in moist all live in moist surroundingssurroundings as well. as well.

How Diverse?How Diverse?

The protists kingdom is one of the most diverse.The protists kingdom is one of the most diverse. Most are unicellularMost are unicellular, although , although some are some are

multicellularmulticellular.. Some are heterotrophs, some are autotrophs Some are heterotrophs, some are autotrophs

and some are…. BOTH!and some are…. BOTH! Some protists cannot move while some others Some protists cannot move while some others

have no problem zipping around their have no problem zipping around their surroundings.surroundings.

How are they grouped?How are they grouped?

Because protists are so varied, Scientist Because protists are so varied, Scientist group them into smaller categories:group them into smaller categories:

Animal-like protists (protozoa)Animal-like protists (protozoa) Plantlike protists (algae)Plantlike protists (algae) Funguslike protists (funguslike)Funguslike protists (funguslike)

Though we will be discussing all protists in Though we will be discussing all protists in class, this powerpoint will focus on the class, this powerpoint will focus on the animal-like protists.animal-like protists.

Animal-like ProtistsAnimal-like Protists

Like animals, Like animals, animal-like protists are animal-like protists are heterotrophs.heterotrophs.

Most are able to move from place to place Most are able to move from place to place to obtain food.to obtain food.

Unlike animals, Unlike animals, animal-like protists are animal-like protists are unicellularunicellular..

Animal-like protists are also called Animal-like protists are also called ProtozoansProtozoans..

ProtozoansProtozoans

Just as protists are split into smaller Just as protists are split into smaller groups, so are groups, so are protozoans. protozoans. They They can be can be split into 4 categories based on the way split into 4 categories based on the way they they movemove and and get foodget food..

The groups are:The groups are: Protozoans with pseudopods (sarcodines)Protozoans with pseudopods (sarcodines) Protozoans with cilia (ciliates)Protozoans with cilia (ciliates) Protozoans with flagella (flagellates)Protozoans with flagella (flagellates) Protozoans that are parasitesProtozoans that are parasites

Protozoans with PseudopodsProtozoans with Pseudopods

Protozoans that have pseudopods are Protozoans that have pseudopods are called called sarcodinessarcodines..

Pseudopod: Means Pseudopod: Means ““false footfalse foot””, , it is a it is a temporary bulge of the cell that temporary bulge of the cell that allows for allows for feeding and movement.feeding and movement.

Pseudopods form when cytoplasm flows Pseudopods form when cytoplasm flows toward one location and the rest of the cell toward one location and the rest of the cell follows.follows.

AmoebaAmoeba

AmoebaAmoeba: Sarcodines that live in either : Sarcodines that live in either water or soil. They feed on bacteria and water or soil. They feed on bacteria and smaller protists.smaller protists.

Like all sarcodines, Like all sarcodines, amoebas move and amoebas move and obtain food with their pseudopods.obtain food with their pseudopods.

AmoebaAmoeba

Protozoans in fresh waterProtozoans in fresh water

Protozoans that live in fresh water have a big Protozoans that live in fresh water have a big problem. Water can move easily through the problem. Water can move easily through the cell membrane and too much can cause the cell cell membrane and too much can cause the cell to burst (passive transport or osmosis).to burst (passive transport or osmosis).

Fortunately for these protozoans, they have a Fortunately for these protozoans, they have a contractile vacuolecontractile vacuole..

A contractile vacuole is a structure that collects A contractile vacuole is a structure that collects and expels excess water from the cell.and expels excess water from the cell.

Protozoans with CiliaProtozoans with Cilia

Protozoans with cilia are called Protozoans with cilia are called ciliatesciliates.. CiliaCilia: Hair like projections from a cell that move : Hair like projections from a cell that move

with a wavelike motion.with a wavelike motion. Just like pseudopods, ciliates use cilia to move Just like pseudopods, ciliates use cilia to move

and obtain food.and obtain food. Ciliates have Ciliates have complex cells. Many have more complex cells. Many have more

than one contractile vacuole and some (like than one contractile vacuole and some (like paramecium), have 2 nuclei.paramecium), have 2 nuclei.

The macronucleus (large) controls everyday The macronucleus (large) controls everyday tasks and the micronucleus (small) aids in tasks and the micronucleus (small) aids in reproduction.reproduction.

ParameciumParamecium

ParameciumParamecium: Ciliates that live mostly in : Ciliates that live mostly in fresh water. fresh water. Like amoebas, paramecia Like amoebas, paramecia feed on bacteria and smaller protists.feed on bacteria and smaller protists.

Like all ciliates, Like all ciliates, paramecia move and paramecia move and obtain food with their cilia.obtain food with their cilia.

ParameciumParamecium

Protozoans with flagellaProtozoans with flagella

Protists with flagella are called Protists with flagella are called flagellatesflagellates.. FlagellaFlagella: Whip-like structure that allows : Whip-like structure that allows

for movement.for movement. Many flagellates form symbiotic Many flagellates form symbiotic

relationships, both good and bad.relationships, both good and bad.

EuglenaEuglena

EuglenaEuglena: A common protozoa that lives in : A common protozoa that lives in fresh water.fresh water.

In sunlight, euglena can make their own In sunlight, euglena can make their own food. food. What makes them bizarre is that What makes them bizarre is that when the lights go down, they become when the lights go down, they become heterotrophic predators!heterotrophic predators!

Like all flagellates, Like all flagellates, euglena move with a euglena move with a flagellum.flagellum.

EuglenaEuglena

Parasitic ProtozoansParasitic Protozoans

Protozoans that are parasitic feed on cells Protozoans that are parasitic feed on cells and bodily fluids of their hosts. and bodily fluids of their hosts.

They move in a variety of ways, some They move in a variety of ways, some have flagella and some depend on their have flagella and some depend on their host for movement.host for movement.

Some have more than one host, relying on Some have more than one host, relying on one organism for transport and one for one organism for transport and one for food.food.