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Microbio Final Verified and Updated
Questions and Answers (100% Correct
Answers)
Name and describe 3 ways that genetic material gets into bacterial cells.
Answer: • Transformation: bacterial cells taking up new DNA (naked, as either
plasmid or fragments) from their environment
• Transduction: process where DNA is transferred from one bacteria to another via a
bacteriophage
• Conjugation: Mediated by the F plasmid, it is a way for an Hfr or F+ cell to give
genetic info to an F- cell, donor DNA replicated by rolling cirlce replication
How was transformation discovered? What are 2 ways it can occur?
Answer: o Transformation was discovered by Griffith when he realized bacteria
could transfer genetic info. Realized this when the dead, virulent cells were mixed
with live, avirulent cells and the mice died. The DNA from the virulent cells was
transformed by the avirulent cells and made the avirulent cells harmful
o It can occur with DNA plasmids or DNA fragments
What is transduction? Know the basic steps associated with this process.
Answer: • Transduction is when DNA is transferred from one cell to another via a
bacteriophage/virus
• Steps: Destruction of host, synthesis of virus DNA and coat proteins, virus capsid
synthesis and virus assembly, lysis of cell and release of phage particles that are now
able to infect other cells
hat is the difference between generalized and specialized transduction?
Answer: o Generalized: DNA from any part of genome is taken up from environment
by mature virion in place of the virus genome
o Specialized: DNA from specific region is taken. It's when integrated virus genomes
excise from host chromosome, and new viral genome contains bacterial genes. When
these new virus genomes enter a new cell, they take genetic info from the previous
host with them. Specialized transduction is successful when newly introduced
bacterial genes become integrated into genome of new host
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What is bacterial conjugation? Know the basic steps associated with this process.
Answer: • Bacterial conjugation is when there is transfer of genetic material
between bacterial cells by direct cell-to-cell contact
• Conjugation between F+ and F-: sex pilus connects cells, F factor replicates inside
F+ and it bridges over to F-, its then integrated into F- (which is now an F+)new F+ can
preform conjugation
• Conjugation between Hfr and F-: sex pilus connectsdonor DNA is replicated by
rolling circle method and transferred through bridge thingConnection breaks and
fragment of donor DNA incorporated into recipient chromosomethe recipient cell is
still an F-, and cannot continue on and preform conjugation
Distinguish between F+, F-, and Hfr strains.
Answer: • F+: have F factor hanging out in cell, but not directly in genome
• F-: do not have F factor
• Hfr: have F factor incorporated into genome
What are point, missense, nonsense, and silent mutations?
Answer: ● Point mutations: result from change in a single base pair, can lead to
single amino acid change in polypeptide or no change at all
● Missense mutations: change in one base pair that changes the amino acid
● Nonsense: change in one base pair, makes for a stop codon
● Silent: mutations that do not effect the protein very much or not at all
What are insertions, deletions, and frameshift mutations?
Answer: • Insertions: addition of single base
• Deletion: removal of a single base
• Frameshift mutations: result of insertions/deletions, dramatic and potentially fatal
changes to the DNA, can give way to complete loss of gene function
Know what mutagens are and some examples.
Answer: • Mutagens: chemical, physical, or biological agents that increase mutation
rae
Microbio Final Verified and Updated
Questions and Answers (100% Correct
Answers)
Name and describe 3 ways that genetic material gets into bacterial cells.
Answer: • Transformation: bacterial cells taking up new DNA (naked, as either
plasmid or fragments) from their environment
• Transduction: process where DNA is transferred from one bacteria to another via a
bacteriophage
• Conjugation: Mediated by the F plasmid, it is a way for an Hfr or F+ cell to give
genetic info to an F- cell, donor DNA replicated by rolling cirlce replication
How was transformation discovered? What are 2 ways it can occur?
Answer: o Transformation was discovered by Griffith when he realized bacteria
could transfer genetic info. Realized this when the dead, virulent cells were mixed
with live, avirulent cells and the mice died. The DNA from the virulent cells was
transformed by the avirulent cells and made the avirulent cells harmful
o It can occur with DNA plasmids or DNA fragments
What is transduction? Know the basic steps associated with this process.
Answer: • Transduction is when DNA is transferred from one cell to another via a
bacteriophage/virus
• Steps: Destruction of host, synthesis of virus DNA and coat proteins, virus capsid
synthesis and virus assembly, lysis of cell and release of phage particles that are now
able to infect other cells
hat is the difference between generalized and specialized transduction?
Answer: o Generalized: DNA from any part of genome is taken up from environment
by mature virion in place of the virus genome
o Specialized: DNA from specific region is taken. It's when integrated virus genomes
excise from host chromosome, and new viral genome contains bacterial genes. When
these new virus genomes enter a new cell, they take genetic info from the previous
host with them. Specialized transduction is successful when newly introduced
bacterial genes become integrated into genome of new host
, Inquire through: | Professional | Confidential Support
What is bacterial conjugation? Know the basic steps associated with this process.
Answer: • Bacterial conjugation is when there is transfer of genetic material
between bacterial cells by direct cell-to-cell contact
• Conjugation between F+ and F-: sex pilus connects cells, F factor replicates inside
F+ and it bridges over to F-, its then integrated into F- (which is now an F+)new F+ can
preform conjugation
• Conjugation between Hfr and F-: sex pilus connectsdonor DNA is replicated by
rolling circle method and transferred through bridge thingConnection breaks and
fragment of donor DNA incorporated into recipient chromosomethe recipient cell is
still an F-, and cannot continue on and preform conjugation
Distinguish between F+, F-, and Hfr strains.
Answer: • F+: have F factor hanging out in cell, but not directly in genome
• F-: do not have F factor
• Hfr: have F factor incorporated into genome
What are point, missense, nonsense, and silent mutations?
Answer: ● Point mutations: result from change in a single base pair, can lead to
single amino acid change in polypeptide or no change at all
● Missense mutations: change in one base pair that changes the amino acid
● Nonsense: change in one base pair, makes for a stop codon
● Silent: mutations that do not effect the protein very much or not at all
What are insertions, deletions, and frameshift mutations?
Answer: • Insertions: addition of single base
• Deletion: removal of a single base
• Frameshift mutations: result of insertions/deletions, dramatic and potentially fatal
changes to the DNA, can give way to complete loss of gene function
Know what mutagens are and some examples.
Answer: • Mutagens: chemical, physical, or biological agents that increase mutation
rae
