Ch 23 Pt 2: Protists

Stramenopiles

• Diatoms

• Brown Algae

• Oomycetes

Diatoms

stramenopiles

unicellular phytoplankton (algae)

• key primary producers

• w/ yellow and brown accessory pigments

silica walls, like a petri dish

• “diatomaceous earth” deposits

no flagellum except in gamete

what color pigments do diatoms have?

yellow, brown, and green

are diatoms unicellular or multicellular?

unicellular phytoplankton

what are the walls of diatoms made of?

siliica

diatoms don’t have flagellum except where?

in the gamete

what are the fossilized remains of diatoms used in?

water filters

diatoms: storing energy as oils help them _____

float

true or false. diatoms are heteroautotrophs.

false. diatoms are photoautotrophs.

diatoms: overview of phototrophs (autotrophs)

• all with chloroplasts containing chlorophyll a

• accessory pigments vary

• some chloroplasts: secondary endosymbiosis (of red algae)

brown algae

stramenopiles

multicellular, mostly marine “seaweeds” (some edible - kelp)

• major primary producers

• w/ brownish accessory pigments w/ chlorophyll

• large thallose form

cell wall w/ cellulose and algin

brown algae: thallus

• blade

• stipe

• holdfast

brown algae ex: kelp

Laminaria and other species

• humans eat it

• algin used as commercial food thickener

oomycetes

stramenopiles

• filamentous, multinucleate, absorptive heterotrophs; some infest plants

  • superficially resemble fungi

• but cell walls w/ cellulose, not chitin

• filamentous growth (mycelia) is diploid

• spores have flagella

oomycetes ex: Phytophthora infestans

“potato late blight” - a plant parasite: caused Irish famine

alveolates

• dinoflagellates

• apicomplexans

• ciliates

true or false. all alveolates have membrane-enclosed sac beneath the cell membrane called alveolus.

true

what is alveolus speculated to aid protists with?

osmoregulation

dinoflagellates

alveolates

• unicellular aquatic heterotrophs or phytoplankton w/ reddish accessory pigments

• pair of flagella in perpendicular grooves

• some are bioluminescent

• many are photosynthetic mutualists within corals

dinoflagellates ex. Pfiesteria

chemoheterotroph, causes lesions on fish

dinoflagellates ex. Akashiwo

photoautotroph: likely that chloroplasts are from secondary endosymbiosis of a red algae

true or false. blooms of species of Dinoflagellates kill fish or create toxic “red tides”

true

dinoflagellates ex. Karena brevis

brevetoxins, neurotoxic, causes a “red tide”

how are some dinoflagellates photoysnthetic?

provide products of photosynthesis (glucose + O2) to corals

ampicomplexans

alveolates

• unicellular parasites of animals; no cell wall

• apical complex helps them enter host cells

• complex life cycles:

  • requires more than one host

  • multiple forms

apicomplexans ex. Plasmodium

causes malaria, carried by mosquitos (Anopheles)

ciliates

alveolates

• unicellular ingestive heterotrophs w/ no cell wall; aquatic

• cilia for feeding and locomotion

• animal-like in function

ciliates ex.

Paramecium

macronucleus

asexual binary fission

micronucleus

sexual reproduction

contractile vacuole

pumps excess water from the cell