Chapters 19, 21 Flashcards
protists
single celled, diverse, polyphyletic (can’t track to common ancestor), many niches, moved by flagella, cilia, or pseudopods
types of protists
opistokonts, amoebozoans, archaeplastids, stramenopiles, alveolates, rhizarians, excavates
opisthokonts
flagellum is posterior, single
-animals
-fungi
choanoflagellates
fungi
- cell wall made of chitin (exoskeleton of insects)
- multicellular or unicellular (yeast)
- absorbtive heterotrophy (enzymes are secreted, break down food, absorbed)
why are fungal infections difficult to treat?
many fungicides are also toxic to animal cells because fungi are closely related to animals
single celled opistikonts
yeast
multicellular opistikonts
strands or hyphae
ex: mushrooms
mycellium
underground portion of mushroom where hyphae are located. where fertilization occurs- hyphae come together and exchange nuclei
fruiting body
above ground portion of mushroom, makes spores by meiosis
examples of plant pathogens
rust, smut
mycorrhizal fungi
- example of symbiosis
- allows trees to take up more minerals from soil, attaches to roots of plants to increase surface area
lichens
fungus + green algae (cyanobacterium)
-example of permanent symbiosis
amoeba
use pseudopod for motility, aquatic, eats via phagocytosis, predator, scavanger, or parasite
how can amoeba move
can shift cytoplasmic content from 1 end of the cell to the other, allows locomotion and used for eating
types of amboebozoans
amboeba, slime molds
physarum
- plasmodial slime mold
- terrestrial
- disperse, then aggregate (coenocytic) to form fruiting bodies where spores form by meiosis
- scavengers, ingest by endocytosis
- move by cytoplasmic streaming
dictyostelium
- cellular slime mold
- amoeba like single cells aggregate into “slug” when dry or starved cells are retained, formed spores (where meiosis occurs)
types of rhizaria
foraminiferans, radiolarians
foraminiferans
- external shells of calcium carbonate
- source of limestone
- pseudopod ensnare plankton
radiolarians
- glassy endoskeleton of calcium carbonate
- largest unicellular eukaryotes
- can have photosynthetic endosymbionts (dinoflagellates)
Types of Archaeplastids
- land plants
- red algae
- green algae
red algae
- photosynthetic
- marine
- chlorphyll a, phycoerythrin
green algae
- chlorphyll a, b
- uni or multicellular
stramenopiles
have unequal flagella
types of stramenopiles
diatoms, brown algae
diatoms
- single celled
- silica in cell walls (upper and lower like a petri dish)
- photosynthetic (storage produces oils, future of biofuels?)
- diatomaceous earth (water filtration systems)
brown algae
- can be multicellular
- sea palms, giant kelp
- photosynthetic (chlorophyll a, c, brown pigment)
- source of emulsifiers of ice cream
what type of chlorophyll does every photosynthetic organism have?
chlorophyll a
how did green algae and land plants develop chloroplast? how do we know?
endosymbiosis, came from more than one membrane surrounding chloroplasts
serial endosymbiosis
more than 2 membranes surrounding chloroplast
brown algae, diatoms, and dinoflagellates have ___ membranes around chloroplast
4
-2 inner membranes from algaeal chloroplast, next out from cell membrane, outermost from host
where did euglenids gain chloroplasts
chloroplast from green algae endosymbiont
alveolates
sacs under cell membrane, single celled
types of alvaeolates
(paramecium) ciliate, dinoflagellates, (plasmodium) apicomplexans
ciliate
- body covered with cilia for motility
- live in fresh water
- sex involves swap of DNA, do not produce offspring
dinoflagellates
-cause the red tides
apicomplexans
- parasite causing malaria
- life cycle in mosquitos, human blood
- has nonfunctional chloroplast, implies ancestors were free living organisms
excavates
unicellular, lacking mitochondria, named for surface groove
types of excavates
giardia, euglena, trypanosome
giardia
- diplomonad
- has many flagella
- lacks mitochondria
- freshwater parasite causing giardiasis
euglena
- euglenid
- photosynthetic
- if in the dark, it eats (autotroph and heterotroph)
- anterior flagellum whips and drags cell behind
trypanosome
-kinetoplastid parasite causing sleeping sickness
events for origin of modern cell
- flexible cell surface
- origin of cytoskeleton
- origin of nuclear envelope
- appearance of digestive vacuoles
- aquired mitochondria and chloroplasts via endosymbiosis
changes in cell structure and function
- more complex cytoskeleton
- formation of ribosome studded membrane
- enclosed DNA in nucleus
- form flagella from microtubules of cytoskeleton
- digestive vacuoles
theory of endosymbiosis
certain organelles are the descendants of prokaryotes engulfed but not digested
