MIBO 3500 Exam 2 UPDATED ACTUAL
Exam Questions and CORRECT Answers
Genome - CORRECT ANSWER✔✔- all the genetic material the organism contains
Vertical transmission - CORRECT ANSWER✔✔- -from parent to offspring
-same species (binary fission)
Horizontal transmission - CORRECT ANSWER✔✔- -transfer of small pieces of DNA from
one cell to another
-different or same species
1) transformation
2) conjugation
3) transduction
Transformation - CORRECT ANSWER✔✔- The process of importing free DNA into
bacterial cells, cells need to be competent to do this (dead bacteria to live)
Dr. Griffith - CORRECT ANSWER✔✔- -studied streptococcus pnemoniae in mice
-"bacteria can transfer info" to each other
Genetic Material Transfer - CORRECT ANSWER✔✔- -S strain on agar plate leads to
illness, and isolation of S colonies
-R strain is not fatal, and isolation of R colonies
-Heat-killed S strain prevents illness and no isolation of colonies
-heat-killed S + living R caused disease and both "S" and "R" were recovered (info sharing
between dead "S" and "R")
How did smooth and rough strains recover if the smooth strains were dead and only the rough
were alive? - CORRECT ANSWER✔✔- -"R" picked up genes from the dead "S"
(transformation) and became pathogenic
,Structure of bacterial genomes - CORRECT ANSWER✔✔- -circular; nucleoid condensed in
middle of cell
-"S" strain has capsule (outer sugar)
-"R" strain no capsule
Conjugation - CORRECT ANSWER✔✔- -horizontal gene transfer between two lives cells
that requires cell-cell contact, pili, and the presence of special transferable plasmids
-bacteria looks for another that does not have the same surface proteins or plasmid
Relaxase - CORRECT ANSWER✔✔- Binds to coupling protein to feed DNA into the pillus
for conjugation
Size of prokaryotic genomes - CORRECT ANSWER✔✔- ~130-14,000 kb (human = >3
million kb)
How does bacteria fit all of the DNA into the cell? - CORRECT ANSWER✔✔- the DNA
gets supercoiled
Compared to humans, how much of the DNA in bacteria consists of non-coding regions? -
CORRECT ANSWER✔✔- very little; bacteria is less than 15% non-coding, while humans
are more than 90% non-coding
Operon - CORRECT ANSWER✔✔- gene that can operate independently or together with
others
Monocistronic mRNA - CORRECT ANSWER✔✔- mRNA that codes for a single type of
protein (bacteria and eukaryotes)
polycistronic mRNA - CORRECT ANSWER✔✔- Single bacterial RNA molecule that
encodes more than one polypeptide chain (bacteria)
, Regulons - CORRECT ANSWER✔✔- a collection of genes or operons with a unified
biochemical purpose (ie. sugar catabolism)
RPOS regulon - CORRECT ANSWER✔✔- "Starvation" regulon (helps bacteria survive
starvation)
Positive supercoiling - CORRECT ANSWER✔✔- DNA is overwound, which is more stable,
but keeps the DNA from being replicated; most often in archaea with a low pH and high temp
Negative supercoiling - CORRECT ANSWER✔✔- DNA is underwound; most often in
bacteria, archaea, and eukaryotes
What is in charge of supercoiling DNA? - CORRECT ANSWER✔✔- Topoisomerases
Type I Topoisomerases - CORRECT ANSWER✔✔- usually single proteins; cleaves one
strand of DNA
Type I Action - CORRECT ANSWER✔✔- 1) Type I protein comes in onto original strand
and introduces cut in DNA
2) Ligase reseals the cut
3) Less # of supercoils than original strand
(can also introduce supercoils, not simply cut them)
Type II Topoisomerases - CORRECT ANSWER✔✔- have multiple subunits; cleave both
strands of DNA
ie. DNA gyrase
quinolone antibiotics target these type of isomerases (prevents supercoiling)
Exam Questions and CORRECT Answers
Genome - CORRECT ANSWER✔✔- all the genetic material the organism contains
Vertical transmission - CORRECT ANSWER✔✔- -from parent to offspring
-same species (binary fission)
Horizontal transmission - CORRECT ANSWER✔✔- -transfer of small pieces of DNA from
one cell to another
-different or same species
1) transformation
2) conjugation
3) transduction
Transformation - CORRECT ANSWER✔✔- The process of importing free DNA into
bacterial cells, cells need to be competent to do this (dead bacteria to live)
Dr. Griffith - CORRECT ANSWER✔✔- -studied streptococcus pnemoniae in mice
-"bacteria can transfer info" to each other
Genetic Material Transfer - CORRECT ANSWER✔✔- -S strain on agar plate leads to
illness, and isolation of S colonies
-R strain is not fatal, and isolation of R colonies
-Heat-killed S strain prevents illness and no isolation of colonies
-heat-killed S + living R caused disease and both "S" and "R" were recovered (info sharing
between dead "S" and "R")
How did smooth and rough strains recover if the smooth strains were dead and only the rough
were alive? - CORRECT ANSWER✔✔- -"R" picked up genes from the dead "S"
(transformation) and became pathogenic
,Structure of bacterial genomes - CORRECT ANSWER✔✔- -circular; nucleoid condensed in
middle of cell
-"S" strain has capsule (outer sugar)
-"R" strain no capsule
Conjugation - CORRECT ANSWER✔✔- -horizontal gene transfer between two lives cells
that requires cell-cell contact, pili, and the presence of special transferable plasmids
-bacteria looks for another that does not have the same surface proteins or plasmid
Relaxase - CORRECT ANSWER✔✔- Binds to coupling protein to feed DNA into the pillus
for conjugation
Size of prokaryotic genomes - CORRECT ANSWER✔✔- ~130-14,000 kb (human = >3
million kb)
How does bacteria fit all of the DNA into the cell? - CORRECT ANSWER✔✔- the DNA
gets supercoiled
Compared to humans, how much of the DNA in bacteria consists of non-coding regions? -
CORRECT ANSWER✔✔- very little; bacteria is less than 15% non-coding, while humans
are more than 90% non-coding
Operon - CORRECT ANSWER✔✔- gene that can operate independently or together with
others
Monocistronic mRNA - CORRECT ANSWER✔✔- mRNA that codes for a single type of
protein (bacteria and eukaryotes)
polycistronic mRNA - CORRECT ANSWER✔✔- Single bacterial RNA molecule that
encodes more than one polypeptide chain (bacteria)
, Regulons - CORRECT ANSWER✔✔- a collection of genes or operons with a unified
biochemical purpose (ie. sugar catabolism)
RPOS regulon - CORRECT ANSWER✔✔- "Starvation" regulon (helps bacteria survive
starvation)
Positive supercoiling - CORRECT ANSWER✔✔- DNA is overwound, which is more stable,
but keeps the DNA from being replicated; most often in archaea with a low pH and high temp
Negative supercoiling - CORRECT ANSWER✔✔- DNA is underwound; most often in
bacteria, archaea, and eukaryotes
What is in charge of supercoiling DNA? - CORRECT ANSWER✔✔- Topoisomerases
Type I Topoisomerases - CORRECT ANSWER✔✔- usually single proteins; cleaves one
strand of DNA
Type I Action - CORRECT ANSWER✔✔- 1) Type I protein comes in onto original strand
and introduces cut in DNA
2) Ligase reseals the cut
3) Less # of supercoils than original strand
(can also introduce supercoils, not simply cut them)
Type II Topoisomerases - CORRECT ANSWER✔✔- have multiple subunits; cleave both
strands of DNA
ie. DNA gyrase
quinolone antibiotics target these type of isomerases (prevents supercoiling)
