MGY377 Final Exam 2026/2027 With
Questions And Answers
Conjugation - correct answer <<<<<💕💕💕✔✔In bacteria, the direct transfer of DNA between two
cells that are temporarily joined.
Phage Transduction - correct answer <<<<<💕💕💕✔✔Non-consensual transfer of DNA from a
bacteriophage to a bacteria
Griffith's experiment - correct answer <<<<<💕💕💕✔✔- Reported in 1928 by Fredrick Griffith,
was the first experiment suggesting that bacteria are capable of transferring genetic information
through a process known as transformation.
- Smooth strain kills mouse. Rough strain doesn't kill mouse. Heat-killed smooth strain doesn't kill
mouse. Heat-killed smooth strain + live rough strain kills mouse.
Avery, MacLeod, McCarty Experiment - correct answer <<<<<💕💕💕✔✔Determined that DNA
was Griffith's "Transforming Factor."
natural competence - correct answer <<<<<💕💕💕✔✔When certain microbes have specific
proteins to facilitate intake of external DNA.
- Examples of naturally competent bacteria:
Gram+ : streptococcus pneumoniae, bacillus subtilis
Gram- : haemophilus influenzae, neisseria gonorrhoeae
artificial competence - correct answer <<<<<💕💕💕✔✔Cells are made permeable to DNA, by
artificially creating favorable conditions that would otherwise not normally occur.
density-dependent competence
- benefits?
, - observed more in gram positive or negative? - correct answer <<<<<💕💕💕✔✔- benefits: 1)
successful uptake of DNA more likely
2) uptake of non-harmful DNA more likely
- Gram positive is more common.
Streptococcus pneumoniae competence
Define:
- Pre-CSP
- ComAB
- CSP
- ComD
- ComE
- ComX
- ComCDE - correct answer <<<<<💕💕💕✔✔Pre-CSP: precursor to CSP
ComAB: transforms pre-CSP into CSP and secretes it through the cytoplasm
CSP: competence-stimulating peptide
ComD: histidine kinase that senses extracellular CSP, leading to the phosphorylation of ComE
ComE: when phosphorylated, turns on transcription of comCDE, comAB, and comX
ComX: minor sigma factor that turns on transcription of late competence proteins
DNA Uptake Sequence - correct answer <<<<<💕💕💕✔✔Required by gram negative bacteria for
efficient transformation to occur.
It is passed through the PilQ-secretin complex.
Plasmid - correct answer <<<<<💕💕💕✔✔- small, circular, supercoiled DNA molecules located in
the cytoplasm of many bacteria
- dispensable for growth under certain conditions
Replicon - correct answer <<<<<💕💕💕✔✔Plasmids defined as having:
Questions And Answers
Conjugation - correct answer <<<<<💕💕💕✔✔In bacteria, the direct transfer of DNA between two
cells that are temporarily joined.
Phage Transduction - correct answer <<<<<💕💕💕✔✔Non-consensual transfer of DNA from a
bacteriophage to a bacteria
Griffith's experiment - correct answer <<<<<💕💕💕✔✔- Reported in 1928 by Fredrick Griffith,
was the first experiment suggesting that bacteria are capable of transferring genetic information
through a process known as transformation.
- Smooth strain kills mouse. Rough strain doesn't kill mouse. Heat-killed smooth strain doesn't kill
mouse. Heat-killed smooth strain + live rough strain kills mouse.
Avery, MacLeod, McCarty Experiment - correct answer <<<<<💕💕💕✔✔Determined that DNA
was Griffith's "Transforming Factor."
natural competence - correct answer <<<<<💕💕💕✔✔When certain microbes have specific
proteins to facilitate intake of external DNA.
- Examples of naturally competent bacteria:
Gram+ : streptococcus pneumoniae, bacillus subtilis
Gram- : haemophilus influenzae, neisseria gonorrhoeae
artificial competence - correct answer <<<<<💕💕💕✔✔Cells are made permeable to DNA, by
artificially creating favorable conditions that would otherwise not normally occur.
density-dependent competence
- benefits?
, - observed more in gram positive or negative? - correct answer <<<<<💕💕💕✔✔- benefits: 1)
successful uptake of DNA more likely
2) uptake of non-harmful DNA more likely
- Gram positive is more common.
Streptococcus pneumoniae competence
Define:
- Pre-CSP
- ComAB
- CSP
- ComD
- ComE
- ComX
- ComCDE - correct answer <<<<<💕💕💕✔✔Pre-CSP: precursor to CSP
ComAB: transforms pre-CSP into CSP and secretes it through the cytoplasm
CSP: competence-stimulating peptide
ComD: histidine kinase that senses extracellular CSP, leading to the phosphorylation of ComE
ComE: when phosphorylated, turns on transcription of comCDE, comAB, and comX
ComX: minor sigma factor that turns on transcription of late competence proteins
DNA Uptake Sequence - correct answer <<<<<💕💕💕✔✔Required by gram negative bacteria for
efficient transformation to occur.
It is passed through the PilQ-secretin complex.
Plasmid - correct answer <<<<<💕💕💕✔✔- small, circular, supercoiled DNA molecules located in
the cytoplasm of many bacteria
- dispensable for growth under certain conditions
Replicon - correct answer <<<<<💕💕💕✔✔Plasmids defined as having:
