Kingdom ProtistaKingdom Protista

If you look at a drop of pond water If you look at a drop of pond water under a microscope, all the "little under a microscope, all the "little creatures" you see swimming around creatures" you see swimming around areare protistsprotists..

All protists have a nucleus and are All protists have a nucleus and are thereforetherefore eukaryoticeukaryotic. .

Protists are either plant-like, animal-like or Protists are either plant-like, animal-like or fungus-like.fungus-like.

Plant-like protists are Plant-like protists are autotrophsautotrophs – – they contain chloroplasts and make they contain chloroplasts and make their own food.their own food.

Animal-like and fungus-like protists Animal-like and fungus-like protists and areand are heterotrophsheterotrophs..

ProtozoansProtozoans are animal-like protistsare animal-like protists ((heterotrophsheterotrophs)) grouped according to grouped according to how they move.how they move.

The wordThe word protozoaprotozoa means "little means "little animal." They are so named because animal." They are so named because many species behave like tiny many species behave like tiny animals—specifically, they hunt and animals—specifically, they hunt and gather other microbes as food.gather other microbes as food.

All protozoa digest their food in All protozoa digest their food in stomach-like compartments called stomach-like compartments called vacuoles <vacuoles <vac-you-ohlsvac-you-ohls>>.. As they As they chow down, they make and give off chow down, they make and give off nitrogen, which is an element that nitrogen, which is an element that plants and other higher creatures plants and other higher creatures can use. can use.

Protozoa move in one of 3 ways: Protozoa move in one of 3 ways: pseudopods, cilia, flagella. pseudopods, cilia, flagella.

Amoebae live in water or moist Amoebae live in water or moist places.places.

They have a cell membrane but They have a cell membrane but no cell wall.no cell wall.

GiardiaGiardia

Plant-like protists arePlant-like protists are algaealgae..

AlgaeAlgae are eukaryotic autotrophs. are eukaryotic autotrophs.

They, along with other eukaryotic They, along with other eukaryotic autotrophs, form the foundation of autotrophs, form the foundation of Earth’s food chains.Earth’s food chains.

They produce much of Earth’s They produce much of Earth’s oxygen.oxygen.

DIATOMS

Fungus-like protists, Fungus-like protists, MyxomycotaMyxomycota and and OomycotaOomycota are decomposers. are decomposers.

Slime MoldsSlime MoldsSlime molds have traits like both fungi and Slime molds have traits like both fungi and animals. During good times, they live as animals. During good times, they live as independent, amoeba-like cells, dining on independent, amoeba-like cells, dining on fungi and bacteria. But if conditions fungi and bacteria. But if conditions become uncomfortable—not enough food become uncomfortable—not enough food available, the temperature isn't right, etc.available, the temperature isn't right, etc.—individual cells begin gathering together —individual cells begin gathering together to form a single structure. The new to form a single structure. The new communal structure produces a slimy communal structure produces a slimy covering and is called a slug because it so covering and is called a slug because it so closely resembles the animal you closely resembles the animal you sometimes see gliding across sidewalks. sometimes see gliding across sidewalks. The slug oozes toward light. When the The slug oozes toward light. When the communal cells sense that they've come communal cells sense that they've come across more food or better conditions, the across more food or better conditions, the slug stopsslug stops