3 large groupings of Protists-protozoans (animal like)-slime molds and water molds (fungi like)-algae (plant like)

Members of a Kingdom that is under reorganization

-animal-like protists•are heterotrophic

-free-living and parasitic types -live in aquatic environments

4 groups of protozoans (we will look at each in more detail)• Mastigophorans (flagellates) • Sarcodines (amoebas) • Sporozoans• Ciliates

-move by one or more flagella-most are free-living-an important parasite is Trypanosoma

-causes sleeping sickness

Found in Human Blood

Giardiathis protist causes cramps and diarrhea

“Hikers disease”from drinking contaminated water

-these are the most closely related to prokaryotes

EuglenaPhotosynthetic flagellates

Chloroplasts are atypical of mastagophorans-most likely came from secondary endosymbiosis Because they are photosynthetic

sometimes they get classified with the plant-like protists

-move and feed by pseudopodia-extension of cell membrane-ingest other protozoans

- phagocytosis (creating a food vacuole)

-       all parasiticPlasmodium causes malaria

Plasmodium has complex life cycle using 2 hosts

Plasmodium feeds off the hemoglobin of the red blood cells

-use cilia to move and feed-found in aquatic environments-nearly all are free-livingex: Paramecium and Stentor

Have a unicellular and multicellular life stagesingle celled “amoeba like” cells can

aggragate to form a multicellular state-find each other by chemotaxis

Single and Multicellular

Found on moist decaying matter

 Plasmodial stage consists of single mass of cytoplasm containing many nuclei

(multinucleate)

Enters this stage when there is a food shortage

Reproductive stage

most are photosynthetic

DINOFLAGELLATES

-unicellular -some photosynthetic, some heterotrophic-outer plates made of cellulose-2 plates come together with flagella between

may cause "red tides" massive fish death from toxins

DIATOMS unicellular, photosynthetic

surrounded by glassy shell of silicon-important base of aquatic food chains

GOLDEN ALGAE (Chrysophyta) May be mixotrophicHave yellow & brown carotene and xanthophylls as accessory pigments

Green algae (Chlorophyta)

-single celled-colonial-multicellular-chlorplasts similar to land plants

ex: Chlamydomona , Volvox

volvox

Chlamydomonas is unicellular while volvox is colonial. Each individual cell in volvox is very similar to chlamydomonas

  

Multicellular algaeKelp, seaweed-are multicellular -may be very large-lack true stems, leaves, roots, and vascular systems

-not plants

-have adapted to life at ocean margins -analogous structures to plants

-thallus seaweed body-holdfast rootlike structure-stipe stemlike structure- blade leaflike structure

GREEN ALGAE (multicellular)Life cycle include an alternation of generations which is similar to plants

These are the closest relative of the plants

BROWN ALGAE

include huge kelp forests

 

RED ALGAE (Rhodophyta)-contain phycobilins

-accessory pigments that absorb blue and green wavelength-have been found at great depths other wavelengths filtered out-found in tropics -some have a hard chalky coating

-may help in formation of reefs