bacteriology 2

Question 1

archaea

Answer 1

Separated from bacteria based on 16S rRNA gene sequence (Woese 1977).
Lack peptidoglycan in the cell wall.
Have different types of lipids in membrane (ether linkage).
Mostly studied for life in extreme environments e.g. deep sea vents.

Question 2

crenarchaetoa

Answer 2

Crenarchaetoa
Thermophilic & hyperthermophilic.
Cool marine planktonic waters.

Question 3

euryarchaetoa

Answer 3

Euryarchaeota
Methanogens – use H2 to reduce CO2 to CH4
Halophiles – live in very high salt environments
Thermoacidophiles – have an optimum growth temperature between 60 – 80C; live at low pH.

Question 4

protista

Answer 4

Unicellular eukaryotes that inhabit water and soil and feed on bacteria and small particles.
Reproduce sexually and asexually.
They absorb nutrients through their outer membranes or ‘wrap themselves around’ their prey to ingest.
Classification system is based primarily on motility and morphology.

Question 5

lytic cycle

Answer 5

Lytic cycle
Attachment
Penetration
Biosynthesis
Maturation
Release

Question 6

lysogeneic cycle

Answer 6

Lysogenic cycle
Virus attaches and injects DNA – incorporation into host = PROPHAGE
Prophage DNA passed on to daughter cells
DNA can excise and enter lytic cycle

Question 7

mutations caused by

Answer 7

Mutations are caused by:
Errors occurring during replication.
Errors occurring during DNA repair – damage cause by:
UV
Chemicals (e.g. H2O2)
Other stresses (e.g. heat)
DNA recombining after gene transfer from an external source.