BIOL 251 EXAM 2 QUESTIONS WITH CORRECT
ANSWERS 2026 RATED A+
1. which of the following would not be a trait that a gene on a plasmid would
code for?- essential metabolic enzyme - pilus synthesis - antibiotic resistance - virulence factor-
ANSWER- essential metabolic enzyme
2. in this case study from class, Methicillin-resistance staphylococcus aureus
(MRSA) strains had acquired virulence factors via what mechanism? - transduction - mutation -
reversion - conjugation - transformation-ANSWER- transduction
3. Which type of gene transfer mechanism was determined to have occurred in
Griffith's experiment?- conjugation- transformation - mutation- transduction- replication-
ANSWER- transformation
4. The transfer of DNA, such as a plasmid, from a bacterial cell to another cell
of the same generation is referred to as- horizontal gene transfer - genetic exchange - vertical
gene transfer- specialized gene transfer- plasmid gain or loss-ANSWER- horizontal gene transfer
5. Frederick Griffith infected mice with a combination of dead encapsulated and
live nonencapsulated bacteria. Why did the mice die?- The two bacterial strains shared
plasmids.- Conjugation occured between the two bacterial strains.- The nonencapsulated
bacteria acquired the gene for capsule production via
biol251 exam 2
Study online at https-ANSWER-//quizlet.com/_gv9xlr
transformation. - The nonencapsulated bacteria mutated, thus acquiring the ability to make a
capsule.- The encapsulated bacteria were revived in the mice and caused a lethal
infection.-ANSWER- The nonencapsulated bacteria acquired the gene for capsule production via
transformation.
6. Which of the following traits would not likely be encoded by a gene on a
, plasmid?- genes encoding enzymes for degradation of unusual substrates- genes encoding
antibiotic resistance- genes encoding essential metabolic enzymes - genes encoding virulence
factors- genes encoding toxins that act as virulence factors-ANSWER- genes encoding essential
metabolic
enzymes
7. Which of the following is NOT a feature of bacterial mutagenesis assays?- Able to measure
the mutagenic potential of chemicals- They are more expensive and complex than testing done
in animals- Less extensive than animal testing- Relatively simple to carry out- Less costly than
animal testing-ANSWER- They are more expensive and complex than testing done in animals
8. Which of the following are features of plasmids? (select all that apply)- Double stranded DNA-
Single or double stranded DNA- part of the bacterial chromosome- may carry resistance genes-
replicate independently-ANSWER- - Double stranded DNA- may carry resistance genes- replicate
independently
9. Which of the following is true about the Ames assay- The test uses a Salmonella strain which
is unable to synthesize its own
Histidine- The test uses a Salmonella strain that is able to synthesize Histidine- The assay
measures the amount of histidine consumed by bacteria
biol251 exam 2
Study online at https-ANSWER-//quizlet.com/_gv9xlr- The assay tests several nutritional
mutants- The assay is designed to measure the rate of spontaneous mutation-ANSWER- The test
uses
a Salmonella strain which is unable to synthesize its own Histidine
10. During conjugation in bacteria- A strand of plasmid DNA is transferred to a recipient cell- A
bacterial transfers its plasmid to another bacterial cell and thus no longer
has a plasmid- A plasmid if transferred vertically to progeny cells- A plasmid if carried to another
bacterial cell by a bacteriophage- A plasmid is picked up from the environment by a bacterial
cell-ANSWER- A strand of plasmid
DNA is transferred to a recipient cell
11. If the results of the Ames assay showed a large number of colonies growing
ANSWERS 2026 RATED A+
1. which of the following would not be a trait that a gene on a plasmid would
code for?- essential metabolic enzyme - pilus synthesis - antibiotic resistance - virulence factor-
ANSWER- essential metabolic enzyme
2. in this case study from class, Methicillin-resistance staphylococcus aureus
(MRSA) strains had acquired virulence factors via what mechanism? - transduction - mutation -
reversion - conjugation - transformation-ANSWER- transduction
3. Which type of gene transfer mechanism was determined to have occurred in
Griffith's experiment?- conjugation- transformation - mutation- transduction- replication-
ANSWER- transformation
4. The transfer of DNA, such as a plasmid, from a bacterial cell to another cell
of the same generation is referred to as- horizontal gene transfer - genetic exchange - vertical
gene transfer- specialized gene transfer- plasmid gain or loss-ANSWER- horizontal gene transfer
5. Frederick Griffith infected mice with a combination of dead encapsulated and
live nonencapsulated bacteria. Why did the mice die?- The two bacterial strains shared
plasmids.- Conjugation occured between the two bacterial strains.- The nonencapsulated
bacteria acquired the gene for capsule production via
biol251 exam 2
Study online at https-ANSWER-//quizlet.com/_gv9xlr
transformation. - The nonencapsulated bacteria mutated, thus acquiring the ability to make a
capsule.- The encapsulated bacteria were revived in the mice and caused a lethal
infection.-ANSWER- The nonencapsulated bacteria acquired the gene for capsule production via
transformation.
6. Which of the following traits would not likely be encoded by a gene on a
, plasmid?- genes encoding enzymes for degradation of unusual substrates- genes encoding
antibiotic resistance- genes encoding essential metabolic enzymes - genes encoding virulence
factors- genes encoding toxins that act as virulence factors-ANSWER- genes encoding essential
metabolic
enzymes
7. Which of the following is NOT a feature of bacterial mutagenesis assays?- Able to measure
the mutagenic potential of chemicals- They are more expensive and complex than testing done
in animals- Less extensive than animal testing- Relatively simple to carry out- Less costly than
animal testing-ANSWER- They are more expensive and complex than testing done in animals
8. Which of the following are features of plasmids? (select all that apply)- Double stranded DNA-
Single or double stranded DNA- part of the bacterial chromosome- may carry resistance genes-
replicate independently-ANSWER- - Double stranded DNA- may carry resistance genes- replicate
independently
9. Which of the following is true about the Ames assay- The test uses a Salmonella strain which
is unable to synthesize its own
Histidine- The test uses a Salmonella strain that is able to synthesize Histidine- The assay
measures the amount of histidine consumed by bacteria
biol251 exam 2
Study online at https-ANSWER-//quizlet.com/_gv9xlr- The assay tests several nutritional
mutants- The assay is designed to measure the rate of spontaneous mutation-ANSWER- The test
uses
a Salmonella strain which is unable to synthesize its own Histidine
10. During conjugation in bacteria- A strand of plasmid DNA is transferred to a recipient cell- A
bacterial transfers its plasmid to another bacterial cell and thus no longer
has a plasmid- A plasmid if transferred vertically to progeny cells- A plasmid if carried to another
bacterial cell by a bacteriophage- A plasmid is picked up from the environment by a bacterial
cell-ANSWER- A strand of plasmid
DNA is transferred to a recipient cell
11. If the results of the Ames assay showed a large number of colonies growing
