Protists II Flashcards
what are Oomycetes
Oomycetes or water molds are fungus like protists. They used to be classified within Fungi, but differ significantly.
The vegetative body of this protist is made up of hyphae or filaments that grow in water as well as in soil and decomposing organisms, and even sometimes within living organisms.
what is the 1st type of spore oomycetes have
Spore type no. 1 is a product of vegetative reproduction.
Hyphae produce a zoosporangium that produces zoospores which have 2 flagellae each and are able to move. They eventually turn into cysts which are a resting or dormant stage that lies in the soil till conditions improve.
what is the second type of spore protists have
if conditions are right, the hyphae can also produce either oogonia, which produce female nuclei, or antheridia, which produce sperm nuclei.
When the hyphae meet and fuse, fertilization of male and female nuclei occurs, resulting in zygotes, also known as oospores. Oospores can also lie dormant,
Oomyctes can be pathogenic, Phytophthora infestans caused potato blight in 19th century Ireland.
what are alveolate
Have membrane bound sacs, alveoli under the plasma membrane
dinoflagellates
apicomplexans
what are Dinoflagellates
- highly variable
- some autotrophic
- some heterotrophic
- others mixotrophic
- typically 2 flagellae
- Endosymbiosis with chloroplasts thought to have occurred after the original evolution of dinoflagellates
- have cellulose cell wall plates called thecae just under the plasma membrane within the cytoplasm
- Cause red tides aka Harmful Algal Blooms (HABs) that kill due to toxins produced by dinoflagellates like Gonyaulax catanella that can be concentrated in shellfish.
what are apicomplexans
- named after an “apical complex” or organelles in their sporozoites
- heterotrophic, but were once mixotrophic
- vestigial chloroplas called an apicoplast
- Plasmodium is one of these that causes malaria, complex life cycle that requires two hosts.
what are in Supergroup Unikonta
Amoebozoans
Mycetozoans
what are Amoebozoans
- group contains Amoebozoans and Opisthokonts
- putting Amoebozoans with Opisthokonts destroyed protist phylogeny
what are Mycetozoans
- this is another group that superficially resemble fungi. Once included in fungi
- have plasmodium (not the malaria thing) diploid phase, aka a coenocute a single cell with hundreds of nuclei
- then grow a sporangium which releases haploid spores, a fruiting body that is multicellular
what is Supergroup Archaeplastida
- descended from a secondary endosymbiotic event with a cyanobacterium
- includes red and green algae, and embryophytes (land plants)
what are Rhodophytes
Rhodophyta
- red algae, red pigment phycoerythrin, red masks the green of chlorophyll. No stage has flagellae
- Alternation of generations, most are heteromorphic. Large sporophyte and small gametophyte. Numerous species that are morphologically identical or isomorphic.
what are chlorophyta
Chlorophyta
- green Algae
- Led to plants
- have important chemical like carotenoids, chlorophyll a and b in common with plants
- Some scientists have suggested a new kingdom called Viridaeplantae (including green algae and plants)
- Very diverse, 3 life cycles (haplontic, diplontic, and haplo-diplontic)
What are Oomycetes
used to be classified with fungi, now we know they are different
Oomycetes have two flagellae, cellulose cell walls, and a diploid hyphal nuclei
Fungi had no flagella, chitin cell walls, and a haploid hyphal nuclei
Oomycetes are very hard to control because they have two types of tough dormant spores
Phytophtora ramorum
- killing tanoaks along the west coast
- attakcs and kills 150 species in 37 genera
- federally quarantines
What are apicomplexans
- apicomplexans
- major human parasite
- named after apical complex of organelles in the sporozoite
- plasmodium = cause of malaria
