Biol 250 exam 3 Test Questions All
Solved Correct.
what are the two types of transposition - Answer conservative and replicative
What transposition with the donor DNA break? - Answer conservative
_____ bacteria continue to spread after a treatment is applied - Answer drug resistant
What are the 4 main antibiotic resistance mechanisms - Answer enzyme inactivation,
enfflux pumps,
metabolic bypasses,
modification of drug target by chromosomal mutations
The enzyme transposase may be coded for by insertion sequences of a - Answer
chromosome or plasmid
A _____ agent is a chemical that inhibits bacteria from reproducing, but does not necessarily kill
them - Answer bacteriostatic
Bactericidal compounds - Answer are biological or chemical agents that kill bacteria
Ciprofloxacin and nalidixic acid are effective antibiotics because they inhibit the activity of -
Answer DNA gyrase
The antibiotic commonly used to treat bacterial infections
a) always act by inhibiting the cross linking of polysaccharides in bacterial cell walls
b) always act by inhibiting bacterial protein synthesis
c) inhibit various biochemical processes that occur in both prokaryotes and eukaryotes
d) none of the above - Answer none of the above
The "targets" for antibiotics used to treat bacterial infections are: - Answer biochemical
processes that are only found in bacteria and not eukaryotic hosts
Beta-lactam antibiotics: - Answer *include penicillins and cephalosporins
, *inhibit the transpeptidase that crosslinks N-acetylglucosamine and N-acetlymuranic acid,
which are polysaccharides found in bacterial cell walls
T or F. Pathogenicity islands are clusters of genes for virulence factors that are located together
on the bacterial chromosome - Answer True
Why is the presence of a cell wall significant from a clinical standpoint? - Answer animal cells
do not have cell walls so antibiotics that target cell walls can selectively destroy invading
microorganisms
T or F. Antibiotic resistance can develop in a bacterium as a result of spontaneous mutation -
Answer
T or F. Mobile resistance genes can encode enzymes that inactivate an antibiotic by altering its
structure - Answer True
Various species of bacteria naturally produce antibiotics. What resistance mechanisms are
utilized by bacteria to survive antibiotics produced by other microbes or from any antibiotics
they may produce themselves? - Answer * modification of the drug target
* enzymatic inactivation
* removal from the cell via efflux pumps
* metabolic bypasses
Some antibiotics inhibit protein synthesis by disruption of translation through interactions with
the - Answer ribosome
The first antibiotic to be characterized was a - Answer β-lactam
Widespread antimicrobial drug resistance is usually passed by - Answer horizontal gene
transfer
Which of the following is a cause of drug-specific resistance in disease-causing organisms? -
Answer Indiscriminate nonmedical use of antimicrobials
A mechanism for penicillin resistance in bacteria is - Answer splitting the β-lactam ring of the
antibiotic
Plasmids can be - Answer beneficial to their host
transferred by conjugation
Solved Correct.
what are the two types of transposition - Answer conservative and replicative
What transposition with the donor DNA break? - Answer conservative
_____ bacteria continue to spread after a treatment is applied - Answer drug resistant
What are the 4 main antibiotic resistance mechanisms - Answer enzyme inactivation,
enfflux pumps,
metabolic bypasses,
modification of drug target by chromosomal mutations
The enzyme transposase may be coded for by insertion sequences of a - Answer
chromosome or plasmid
A _____ agent is a chemical that inhibits bacteria from reproducing, but does not necessarily kill
them - Answer bacteriostatic
Bactericidal compounds - Answer are biological or chemical agents that kill bacteria
Ciprofloxacin and nalidixic acid are effective antibiotics because they inhibit the activity of -
Answer DNA gyrase
The antibiotic commonly used to treat bacterial infections
a) always act by inhibiting the cross linking of polysaccharides in bacterial cell walls
b) always act by inhibiting bacterial protein synthesis
c) inhibit various biochemical processes that occur in both prokaryotes and eukaryotes
d) none of the above - Answer none of the above
The "targets" for antibiotics used to treat bacterial infections are: - Answer biochemical
processes that are only found in bacteria and not eukaryotic hosts
Beta-lactam antibiotics: - Answer *include penicillins and cephalosporins
, *inhibit the transpeptidase that crosslinks N-acetylglucosamine and N-acetlymuranic acid,
which are polysaccharides found in bacterial cell walls
T or F. Pathogenicity islands are clusters of genes for virulence factors that are located together
on the bacterial chromosome - Answer True
Why is the presence of a cell wall significant from a clinical standpoint? - Answer animal cells
do not have cell walls so antibiotics that target cell walls can selectively destroy invading
microorganisms
T or F. Antibiotic resistance can develop in a bacterium as a result of spontaneous mutation -
Answer
T or F. Mobile resistance genes can encode enzymes that inactivate an antibiotic by altering its
structure - Answer True
Various species of bacteria naturally produce antibiotics. What resistance mechanisms are
utilized by bacteria to survive antibiotics produced by other microbes or from any antibiotics
they may produce themselves? - Answer * modification of the drug target
* enzymatic inactivation
* removal from the cell via efflux pumps
* metabolic bypasses
Some antibiotics inhibit protein synthesis by disruption of translation through interactions with
the - Answer ribosome
The first antibiotic to be characterized was a - Answer β-lactam
Widespread antimicrobial drug resistance is usually passed by - Answer horizontal gene
transfer
Which of the following is a cause of drug-specific resistance in disease-causing organisms? -
Answer Indiscriminate nonmedical use of antimicrobials
A mechanism for penicillin resistance in bacteria is - Answer splitting the β-lactam ring of the
antibiotic
Plasmids can be - Answer beneficial to their host
transferred by conjugation
