CHARACTERISTICS OF PROTISTS

Simplest eukaryotesErnest Haeckel coined the term protista in

1886mostly unicellular, some are multicellularcan be heterotrophic or autotrophicmicroscopic or macroscopicmost live in water (though some live in

moist soil or even the human body)ALL are eukaryotic (have a nucleus)A protist is any organism that is not a plant,

animal or fungus.

Plantlike ProtistsThe algae, euglena, and dinoflagellates are

representatives of the plantlike protists.Live in the aquatic environment (fresh and

salt water).

ALGAE

Algae is multicellular or unicellular, but the single celled type can’t be seen without a microscope.

Thrive in aquatic environmentThey mostly use photosynthesis, but some

eat other protists or absorb nutrients for food

Described as thallus body.They are known as algae. (Alga- singular)Macroscopic algae are referred to as

seaweeds.

EuglenaLive mostly in fresh waterHave plant and animal

characteristicsUse photosynthesis, but

when there’s not enough light, they are consumers

Some don’t use photosynthesis at all because they don’t have chloroplast. Instead, they just eat other protists or take in nutrients 

Move by using flagella to push them through the water

Dinoflagellates Live mostly in salt water, but some are found in fresh water and snow.

Have flagella that make the protists spin

Most use photosynthesis, but some get food as consumers, decomposers, or parasites

They are sometimes red and produce a strong poison

When they produce very fast, they cause red tide, where the water turns red and the shellfish eat it, making the shellfish poisonous to all vertebrates.

Animal-like protists: Protozoansthey are heterotrophs and can move around.

They are multicellular. Their means of movement are through their flagella and cilia.

Amoeba- moves using pseudopodia ( “false feet” ), which are like extensions of the cytoplasm.

Ingests food by surrounding and engulfing food (endocytosis)

Reproducing by binary fission (mitosis)

can cause amebic dysentery in humans – diarrhea and stomach upset from drinking contaminated water

Animal-like protists: ProtozoansPARAMECIUM

move using ciliaexhibits avoidance

behaviorreproduces asexually

(binary fission) or sexually (conjugation)

outer membrane -pellicle- is rigid and paramecia are always the same shape, like a shoe

Animal-like protists: Protozoans

Trypanosoma group of

unicellular parasitic flagellate protozoa.

cause various diseases, including the fatal human diseases sleeping sickness

Funguslike protistsThrive in moist, damp places where there is

a lot of rotting organic matter.Fungus-like protists are heterotrophs with

cell walls.  All fungus-like protists are able to move at some point in their lives.  There are essentially three types of fungus-like protists:  water molds, downy mildews, and slime molds.

Often brightly coloredChange form during life cycleTend to live in damp locations