MICR 4423 EXAM 5 QUESTIONS AND ANSWERS
What is antibiotic selection? - Answers :the survival of antibiotic-resistant cells within a
larger population in antibiotic-sensitive cells.
The most resistant cell in the populations survive the best in the presence of antibiotics
Where can antibiotic selection occur? - Answers :anywhere that bacteria and antibiotics
is present
Name a common use for antibiotic selection in microbiological research. - Answers
:identifying particular cells that contain a DNA molecule of interest
- ex: plasmid, transform cells w a plasma and plate them on an agar
Why does virtually every plasmid used for scientific research contain an antibiotic
resistance marker? - Answers :so cells that contain plasma can be easily identified
Imagine that you have a sample of bacteria that is a mixture of ampicillin-resistant cells
and ampicillin-sensitive cells. How could you isolate ampicillin-resistant cells? - Answers
:take the sample of bacteria, dilute it, and plate it on an agar plate with ampicillin, and
the ones that grow into colonies are ampicillin-resistant
What antibiotic or class of antibiotics do cells containing the BLA marker become
resistant to? - Answers :ampicillin
What antibiotic or class of antibiotics do cells containing the AAC marker become
resistant to? - Answers :kanamycin
What antibiotic or class of antibiotics do cells containing the CAT marker become
resistant to? - Answers :chloramphenicol
What are the Tet-ON and Tet-OFF systems typically used for? - Answers :the
inducibility control gene expression in eukaryotic systems
What is a typical inducer of the Tet-ON or Tet-OFF system? - Answers :doxycycline
TET-ON without tet: - Answers :repressor binds to operator and no transcription occurs
TET-ON - Answers :acts as a repressor to gene expression
TET-OFF - Answers :acts as an inducer to gene expression
TET-OFF with out tet: - Answers :transactivation binds to the repressor and allows
transcription to occur
, TET-OFF with TET: - Answers :the TA and repressor bind and leave the operator
Tet-ON with TET: - Answers :activate gene expression by making the repressor leave
the operator.
What is a typical way of administering Tet to an animal? - Answers :add to drinking
water
Contrast how antibiotics are regulated in the United States and northern Europe with
how they are regulated in most other countries. - Answers :US and northern europe:
prescribed by a doctor and filled by a pharmacist
other countries: over-the-counter
Pro of having antibiotics available by prescription only. - Answers :- Dr. prescribes the
right Abx and course first time
- less risk of resistance/encouraging it
- choice of ABX + compliance
- product quality
Con of having antibiotics available by prescription only. - Answers :- need good health
infrastructure
- need pharmacies
- doesn't guarantee compliance
- EXPENSIVE
Pro of having antibiotics available over the counter. - Answers :- no Dr. needed
- save time
- cheaper
- faster
Con of having antibiotics available over the counter. - Answers :- no oversight
- inappropriate treatment
- the patient could choose the wrong antibiotic
- increased risk of antibiotic resistance
What is the most prevalent/biggest use of antibiotics worldwide and in the USA? -
Answers :agriculture and raising animals for human food production
What effects do antibiotics have when added to animal feed? - Answers :increased
growth promotion and reduce incident of infectious disease
What is meant by growth promotion? - Answers :- faster time to market weight and use
less to get there, more protein to fat in meat
- lowers the chance of disease/infectious disease
What is antibiotic selection? - Answers :the survival of antibiotic-resistant cells within a
larger population in antibiotic-sensitive cells.
The most resistant cell in the populations survive the best in the presence of antibiotics
Where can antibiotic selection occur? - Answers :anywhere that bacteria and antibiotics
is present
Name a common use for antibiotic selection in microbiological research. - Answers
:identifying particular cells that contain a DNA molecule of interest
- ex: plasmid, transform cells w a plasma and plate them on an agar
Why does virtually every plasmid used for scientific research contain an antibiotic
resistance marker? - Answers :so cells that contain plasma can be easily identified
Imagine that you have a sample of bacteria that is a mixture of ampicillin-resistant cells
and ampicillin-sensitive cells. How could you isolate ampicillin-resistant cells? - Answers
:take the sample of bacteria, dilute it, and plate it on an agar plate with ampicillin, and
the ones that grow into colonies are ampicillin-resistant
What antibiotic or class of antibiotics do cells containing the BLA marker become
resistant to? - Answers :ampicillin
What antibiotic or class of antibiotics do cells containing the AAC marker become
resistant to? - Answers :kanamycin
What antibiotic or class of antibiotics do cells containing the CAT marker become
resistant to? - Answers :chloramphenicol
What are the Tet-ON and Tet-OFF systems typically used for? - Answers :the
inducibility control gene expression in eukaryotic systems
What is a typical inducer of the Tet-ON or Tet-OFF system? - Answers :doxycycline
TET-ON without tet: - Answers :repressor binds to operator and no transcription occurs
TET-ON - Answers :acts as a repressor to gene expression
TET-OFF - Answers :acts as an inducer to gene expression
TET-OFF with out tet: - Answers :transactivation binds to the repressor and allows
transcription to occur
, TET-OFF with TET: - Answers :the TA and repressor bind and leave the operator
Tet-ON with TET: - Answers :activate gene expression by making the repressor leave
the operator.
What is a typical way of administering Tet to an animal? - Answers :add to drinking
water
Contrast how antibiotics are regulated in the United States and northern Europe with
how they are regulated in most other countries. - Answers :US and northern europe:
prescribed by a doctor and filled by a pharmacist
other countries: over-the-counter
Pro of having antibiotics available by prescription only. - Answers :- Dr. prescribes the
right Abx and course first time
- less risk of resistance/encouraging it
- choice of ABX + compliance
- product quality
Con of having antibiotics available by prescription only. - Answers :- need good health
infrastructure
- need pharmacies
- doesn't guarantee compliance
- EXPENSIVE
Pro of having antibiotics available over the counter. - Answers :- no Dr. needed
- save time
- cheaper
- faster
Con of having antibiotics available over the counter. - Answers :- no oversight
- inappropriate treatment
- the patient could choose the wrong antibiotic
- increased risk of antibiotic resistance
What is the most prevalent/biggest use of antibiotics worldwide and in the USA? -
Answers :agriculture and raising animals for human food production
What effects do antibiotics have when added to animal feed? - Answers :increased
growth promotion and reduce incident of infectious disease
What is meant by growth promotion? - Answers :- faster time to market weight and use
less to get there, more protein to fat in meat
- lowers the chance of disease/infectious disease
