Lecture 8 Flashcards
where do prokaryotes live?
in all environments of earth
what helps prokaryotes resist heat and drought?
endospores
what state do some prokaryotes enter in harsh enviroments?
Viable-but-not-culturable (VBNC) state
will go back to normal in favorable conditions
how do prokaryotes (both bacteria and Achaea) reproduce?
asexually via binary fission
what is binary fission?
basically cloning itself
not much variety
similar to mitosis
3 reasons why can prokaryote populations have high genetic diversity despite reproducing via binary fission?
rapid reproduction, mutations, and horizontal gene transfer
what is horizontal gene transfer?
DNA passed from one bacterium to another
what do many cyanobacteria form?
long filaments (i.e. colonies)
what do heterocysts do in cyanobacteria?
fix nitrogen from N2
what happened to obligate anerobic organisms during the ‘oxygen revolution’
many dies and led to a mass extinction
what are methanogens?
anaerobic chemoautotrophs
use H gas as an energy source
produce methane
what is special about thermophilic archaea
able to tolerate extremely hot temperatures due to their unique cellular membrane
what is an adaptation of halobacteria? (etremophiles that live in salty enviroments)
they have a unique protein called halorhodopsin
light activated chloride pump which pumps chloride into the cells to prevent water loss
what is halorhodopsin
light activated chloride pump which pumps chloride into the cells to prevent water loss
