chap 27 Flashcards
(32 cards)
Identify the differences between Bacteria, Archaea, and Eukarya, and the evolutionary relationships between the 3 groups
11
5 characteristics
Prokaryotes - Bacteria and Archaea domains
Eukaryotes - Eukaryra domain (animals, plants, fungi, protists)
Archaea is more closely related to eukaryra.
Prokaryotic cells are wayyy smaller.
Archaea and eukaryotic cells similarities:
- cytoplasm
- histones (proteins in dna repli)
- ribosomes.
- NO nucleus
- circular DNA
Many Archaea are extremophiles
Some Bacterias are extremophiles. more are not.
Bacterias are extremely diverse.
Mitochondria and plastids orginated from bacteria (endosymbiosis).
Horizontal gene transfer = bact + arch
- Transduction (viral),
- transformation (dna from disintegrated cell),
- conjugation (mating).
-Prokaryotes produce asexually only
Explain the ecological roles of prokaryotes
3
-Many fix nitrogen to be used by producers
-Vastly diverse, can be pathogens, producers, decomposers, symbionts, etc.
-Produce organic carbon, may produce up to 50% of the atmospheric oxygen
Explain the ecological roles of decomposers
Releases CO2, breaks down carbon into minerals to be released back into the environment.
important for global carbon cycle.
Explain the ecological roles of producers
-Convert CO2 into O2
-Main food source to life
Explain the ecological roles of nitrogen fixers
Bacteria convert atmospheric N2 into usable compounds (nitrates, ammonium) for plants to be able to metabolize
Explain the ecological roles of pathogens
regulate populations and ecosystems
Explain the ecological roles of various symbioses
2
- Mutualistic bacteria - help each other with nutrients
- Pathogenic bacteria - Cause illness –> decreases abundant pop.
Horizontal gene transfer
3
Transformation, transduction, and conjugation
it is used in 80% of the bac and arch
allows diff species of bac and arch to become immune or pathogenic from the DNA of another.
importance of horizontal gene transfer in the evolution eukaryotic groups
the endosymbiosis of mitochondria and plastids is a form of horizontal gene transfer from bacteria to eukaryotes that impacted eukaryotes.
coccus
spherical shape bac
bacillus
rod-shaped bac
spirillus
spiral shape bac
vibros
comma-shaped bac
cell wall types
gram + and gram -
gram +
high amount of peptidoglycan and only an inner cell membrane
stains purple
thick wall.
gram -
thin peptidoglycan wall. have a plasma membrane anddd a lipopolaysaccharide-rich outer envelope.
turn pink
photoautotroph
e source, c source
e source - light
c source - co2
chemoautotroph
e source - inorganic compounds
c source - co2
photoheterotroph
e source - light
c source - organic compounds
chemoheterotroph
e source - organic compounds
c source - organic compounds
obligated aerobes
need O2
facultative aerobes
can use O2 or not
obligate anaerobes
cannot tolerate O2 – can die from it
aerotolerant anaerobes
don’t use O2 but cannot die from it
