5 types of chromalveolates
- diatoms
- dinoflagellates
- brown algae
- water molds
- ciliates
2 types of rhizarians
- foraminiferans
- radiolorians
2 types of unikonts
- plasmodial slime molds
- cellular slime molds
2 types of archeaplastids
- red algae
- green algae
Diatoms
unicellular, glassy cell wall containing silica, autotrophic protist
Diatoms cell wall consists of ..
two halves that fit together like the top and bottom of a shoe box
Diatoms found in..
marine AND freshwater environments
The organic molecules diatoms produce are an important..
food source in all aquatic environments
Food from diatoms are stored in the form of
oil and sugar droplets
The advantage of diatoms oil droplets is two fold
- rich source of energy
- oil makes diatoms buoyant and keeps them floating near the surface of water where sunlight is
Fossilized diatoms form..
sediment of the diatomaceious earth
Dinoflagellates commonly found on
marine and freshwater plankton
Dinoflagellates are either..
- autotrophs
- heterotrophs
- mixotrophic
Dinoflagellates blooms can cause.. and produces..
- warm coastal waters to turn a pinkish orange (called red tide)
- produce toxins which have killed large quantities of fish
Brown algae
large and complex, multicellular, autotrophic, brown color due to pigments in chloroplasts, most marine
Brown algae is what we commonly call..
seaweed
Water moulds
heterotrophic and unicellular, fungus like, decompose dead plants and animals in freshwater habitats
Sometimes parasitic water moulds grow on,..
the skin and gills of fish
Ciliates
large and diverse group, use cilia for movement (swim/crawl) and feeding, unicellular, heterotrophs and mixotrophs (ex: paramecium)
Plasmodium
also a chromalveolates, causative agents of malaria transmitted by mosquitos
Rhizarians referred to as..
amoebas
Rhizarians
protists that mover and feed using pseudopodia, are different than those of other amoebas because they’re threadlike
Alternative amoebas have..
lobe like pseudopodia
Foraminiferends
found in ocean and freshwater. have tests, pseudopodia extend through small holes of the tests
Tests
porous shells composed of organic material hardened by calcium carbonate
Pseudopodia
used for feeding and movements, fossilized tests form sedimentary rock
Radiolarians
produce an internal skeleton made of silk, surrounded by a test made of organic material, mostly marine
What happens to radiolarians when they die
settle to the bottom of the ocean and become sediments
Excavata
autotrophic, heterotropic, and mixotrophic protists. represent the most ancient surviving lineage of eukaryotes.
Excavata have a modified..
mitochondria so no electron transport chain.
How excavata produce ATP
anaerobic, use of glycolysis and other pthways
Example of excavata
Giardia intestinalis, waterborne parasite causing servere diarrhea
Parasites..
derive nutrition from their host harming the host in the process
Sexually transmitted parasite belonging to excavata
trichomonas vaginalis
Trypanasoma spp.
excavata. parasites that can be passed to humans via insect bites (african sleeping sickness spread by tsetse fly)
Euglena spp.
excavata. common inhabitants of pond water
Unikonts
use pseudopodia (temporary lobe like extensions of cell) to move and feed
Unikonts group includes
free living amoebas, some parasitic amoebas, plasmodial slime molds, and cellular slime molds
Plasmodial slime molds
commonly found where there is moist decaying organic matter. often bright pigment. engulfs food by phagocytosis
What plasmodium means
not multicellular, single multinucleate mass of cytoplasm, undivided by plasma membranes (different than plasmodium that causes malaria)
Plasmodial extends pseudopodia through
soil and rotting logs
How cytoplasm moves through plasmodia slime mold
cytoplasm moves through fine channels in one direction and then the opposite, these pulsing flows help to distribute nutrients and oxygen
When food and water are limited the plasmodium mold..
stops growing and differentiates into reproductive structures that produce spores
When conditions for the plasmodium mols become favourable the spores..
release haploid cells that fuse to a zygote allowing the life cycle to continue
Cellular slime molds common on
rotting logs and decaying organic matter
Cellular slime mols usually exist as
solo amoeboid cells and when nutrients are scare they swarm together forming a slug like clump of cells that travels for a short period
When some of the cellular slime mold cells dry up..
they form stalk and the stalk supports asexual reproductive structure where cells develop spores
Archaeplastids
mainly autotrophic, red algae, green algae, and land plants
Red algae
live in warm coastal waters of the tropics, multicellular, usually soft bodied although some have cell walls with chalky deposits (commonly found in coral reefs)
Red algae red because
extra pigment that masks the green chlorophyll
Green algae
unicellular, colonial, multicellular members. generally complex life cycles
Life cycle of green algae (multicellular Ulva)
characterized by an alternation of generations, multicellular diploid form 2n alternates with multicellular haploid n form. this alternation occurs in multicellular algae and plants
Gametophytes
multicellular haploid form
Sporophytes
multicellular diploid form
1st step of evolution of multicellularity
ancestral colony of flagellated protists may have formed. a cell divided and offspring remained attached to another
2nd step of evolution of multicellularity
cells of the colony may have become slightly specialized and interdependent. different cell types became more and more efficient at performing certain tasks
3rd step of evolution of multicellularity
additional specialization may have led to a differentiation in between sex cells and non reproductive cells