MGY377 Final Exam Questions & Answers Test QUESTIONS AND
VERIFIED SOLUTIONS |2026| ELABORATED &DETAILED ANSWERS!!
Transformation - (answer)process in which one strain of bacteria is changed by a gene or genes from
another strain of bacteria
Conjugation - (answer)In bacteria, the direct transfer of DNA between two cells that are temporarily
joined.
Phage Transduction - (answer)Non-consensual transfer of DNA from a bacteriophage to a bacteria
Griffith's experiment - (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 - (answer)Determined that DNA was Griffith's "Transforming
Factor."
natural competence - (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 - (answer)Cells are made permeable to DNA, by artificially creating favorable
conditions that would otherwise not normally occur.
, MGY377 Final Exam Questions & Answers Test QUESTIONS AND
VERIFIED SOLUTIONS |2026| ELABORATED &DETAILED ANSWERS!!
density-dependent competence
- benefits?
- observed more in gram positive or negative? - (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 - (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 - (answer)Required by gram negative bacteria for efficient transformation to
occur.
VERIFIED SOLUTIONS |2026| ELABORATED &DETAILED ANSWERS!!
Transformation - (answer)process in which one strain of bacteria is changed by a gene or genes from
another strain of bacteria
Conjugation - (answer)In bacteria, the direct transfer of DNA between two cells that are temporarily
joined.
Phage Transduction - (answer)Non-consensual transfer of DNA from a bacteriophage to a bacteria
Griffith's experiment - (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 - (answer)Determined that DNA was Griffith's "Transforming
Factor."
natural competence - (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 - (answer)Cells are made permeable to DNA, by artificially creating favorable
conditions that would otherwise not normally occur.
, MGY377 Final Exam Questions & Answers Test QUESTIONS AND
VERIFIED SOLUTIONS |2026| ELABORATED &DETAILED ANSWERS!!
density-dependent competence
- benefits?
- observed more in gram positive or negative? - (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 - (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 - (answer)Required by gram negative bacteria for efficient transformation to
occur.
