BIOC 385 Exam 4 questions well
answered graded A+ updated
in the figure shown below of an E. coli replication fork, which protein is responsible for relieving
torsional stress? - correct answer ✔✔gyrase
based on the figure shown below, cleavage followed by rejoining at which sites would lead to no
recombination or loss of genetic info? - correct answer ✔✔1 and 3
match the name of the DNA repair mechanisms with the correct description - correct answer
✔✔1- fxns w DNA repair mechanism with the correct description
2- requires an endonuclease
3- is needed to repair chemical damage
4- repairs nucleotide bases
what is a holliday junction? - correct answer ✔✔the location in a DNA recombination
intermediate where DNA strands from different DNA molecules are crossed over, which links the
2 DNA molecules together
AZT is such a good HIB drug because it - correct answer ✔✔prevents new DNA from being
replicated
if 15N DNA is replication using conservative replication in 15N media, the outcome would be
that new DNA has - correct answer ✔✔one high density and one low density strand
what is the fxn of the MutS-MutL-MutH protein complex - correct answer ✔✔none
, what accounts for the high fidelity of DNA polymerization? - correct answer ✔✔active site
geometry ensures that only correct sized nucleotide base pairs are formed, and 3' to 5'
proofreading removes incorrect nucleotides
the processes of DNA replication and RNA transcription in E. coli are similar in some respects
and different in others. select 3 statements - correct answer ✔✔1- the direction of
polymerization is 5' to 3'
2- the direction of enzyme movement on the template strand is 3' to 5'
3- a specific region of the DNA is recognized and bound by the polymerase
how is the ames test used to quantitate mutagenic potential of chemical compounds? select 2
best answers - correct answer ✔✔1- the chemical compound to be tested is added to a filter
paper disk and placed on agar plates containing the tester Salmonella strain
2- the salmonella test strain used in the ames test contains a mutation in the histidine
biosynthetic pathway, which is used to identify compounds that induce back mutations to
permit bacterial growth on histidine free plates
why does RNA contain uracil and DNA contain thymine? choose the one best answer - correct
answer ✔✔Spontaneous cytosine deamination generates uracil, which base pairs with adenine
during replication, and thereby converts a C-G base pair to a T-A base pair.
francis crick hypothesized that the genetic code must require 3 nucleotides in the mRNA to
specify each amino acid based on a simple calculation. what was the logic behind this
calculation? - correct answer ✔✔based on the number of known amino acids and the number
of known nucleotide bases
the shine-dalgarno sequence of mRNA base pairs with the (blank) rRNA within the prokaryote
(blank) ribosomal subunit - correct answer ✔✔16S; 30S
if the following mRNA was added to a cell-free translation system, how many unique protein
sequences would be generated? - correct answer ✔✔3
answered graded A+ updated
in the figure shown below of an E. coli replication fork, which protein is responsible for relieving
torsional stress? - correct answer ✔✔gyrase
based on the figure shown below, cleavage followed by rejoining at which sites would lead to no
recombination or loss of genetic info? - correct answer ✔✔1 and 3
match the name of the DNA repair mechanisms with the correct description - correct answer
✔✔1- fxns w DNA repair mechanism with the correct description
2- requires an endonuclease
3- is needed to repair chemical damage
4- repairs nucleotide bases
what is a holliday junction? - correct answer ✔✔the location in a DNA recombination
intermediate where DNA strands from different DNA molecules are crossed over, which links the
2 DNA molecules together
AZT is such a good HIB drug because it - correct answer ✔✔prevents new DNA from being
replicated
if 15N DNA is replication using conservative replication in 15N media, the outcome would be
that new DNA has - correct answer ✔✔one high density and one low density strand
what is the fxn of the MutS-MutL-MutH protein complex - correct answer ✔✔none
, what accounts for the high fidelity of DNA polymerization? - correct answer ✔✔active site
geometry ensures that only correct sized nucleotide base pairs are formed, and 3' to 5'
proofreading removes incorrect nucleotides
the processes of DNA replication and RNA transcription in E. coli are similar in some respects
and different in others. select 3 statements - correct answer ✔✔1- the direction of
polymerization is 5' to 3'
2- the direction of enzyme movement on the template strand is 3' to 5'
3- a specific region of the DNA is recognized and bound by the polymerase
how is the ames test used to quantitate mutagenic potential of chemical compounds? select 2
best answers - correct answer ✔✔1- the chemical compound to be tested is added to a filter
paper disk and placed on agar plates containing the tester Salmonella strain
2- the salmonella test strain used in the ames test contains a mutation in the histidine
biosynthetic pathway, which is used to identify compounds that induce back mutations to
permit bacterial growth on histidine free plates
why does RNA contain uracil and DNA contain thymine? choose the one best answer - correct
answer ✔✔Spontaneous cytosine deamination generates uracil, which base pairs with adenine
during replication, and thereby converts a C-G base pair to a T-A base pair.
francis crick hypothesized that the genetic code must require 3 nucleotides in the mRNA to
specify each amino acid based on a simple calculation. what was the logic behind this
calculation? - correct answer ✔✔based on the number of known amino acids and the number
of known nucleotide bases
the shine-dalgarno sequence of mRNA base pairs with the (blank) rRNA within the prokaryote
(blank) ribosomal subunit - correct answer ✔✔16S; 30S
if the following mRNA was added to a cell-free translation system, how many unique protein
sequences would be generated? - correct answer ✔✔3
