BCHM 307 Exam 2024 with Questions Solved
100% Correct |Verified Solutions
Which DNA strand is replicated exclusively in a discontinuous fashion?
a. Leading strand
b. Forward strand
c. Reverse strand
d. The strand read in 5' to 3' direction
e. Lagging strand - Answer e. Lagging strand
Which tumor suppressor gene is found to be mutated in at least half of all human
tumors?
a. p53
b. BRCA1
c. BRCA2
d. Retinoblastoma - Answer a. p53
What is the nucleophile in the DNA polymerase mechanism?
a. An oxygen anion on the -phosphate of the dNTP
b. The oxygen on the -phosphate of the dNTP
c. The 3' hydroxyl on the deoxyribose
d. The 5' hydroxyl on the deoxyribose
e. The oxygen on the -phosphate of the dNTP - Answer c. The 3' hydroxyl on the
deoxyribose
Synthesis of telomeres requires the enzyme ___, which is a type of ___.
,a. Topoisomerase, RNA-specific nuclease
b. Telomerase, helicase
c. Topoisomerase, ligase
d. Telomerase, reverse transcription - Answer d. Telomerase, reverse transcription
Besides the obvious role of keeping DNA in a single stranded state, what do single-
strand binding proteins do?
a. Prevent supercoiling
b. Aid in the formation of hairpin structures
c. Aid DNA polymerase with DNA binding
d. Protect single strand DNA from nucleases - Answer d. Protect single strand DNA from
nucleases
What is the purpose of DNA helicase?
a. Separation of double stranded DNA into single stranded DNA in front of DNA
polymerase
b. Removal of negative supercoiling to allow for replication
c. Conversion of single stranded DNA to double stranded DNA behind DNA polymerase
d. Removal of positive supercoiling to allow for replication - Answer a. Separation of
double stranded DNA into single stranded DNA in front of DNA polymerase
Histone proteins that bind to areas of DNA that are highly transcribed are often ___ on
___ residues.
a. Acetylated, histidine
b. Phosphorylated, serine
c. Phosphorylated, tyrosine
d. Methylated, lysine
,e. Acetylated, lysine - Answer e. Acetylated, lysine
What effect does a topoisomerase have on DNA?
a. Changed B-form DNA to A-form
b. Changes the supercoiling of DNA
c. Converts double stranded DNA to single stranded DNA
d. Denatures DNA - Answer b. Changes the supercoiling of DNA
Which type of DNA repair is used to remove and replace a single modified base that
cannot be converted back to a normal base by a direct repair process?
a. Mismatch repair
b. Base excision repair
c. Nucleotide excision repair
d. DNA photolyase - Answer b. Base excision repair
Which of the following is found in high concentrations in telomeres?
a. G
b. C
c. T
d. A
e. Pyrimidines - Answer a. G
Which of the following best describes the nucleic acid complex formed during DNA
polymerization?
a. One DNA-RNA hybrid and one single stranded DNA
b. One DNA-RNA hybrid with other DNA strand bound to an RNA molecules on RNA
polymerase
, c. There is no interaction between growing RNA and DNA
d. Two DNA-RNA hybrids since both DNA strands are transcribed simultaneously
e. None of the above - Answer a. One DNA-RNA hybrid and one single stranded DNA
Addition of a(n) ___ group to certain lysine residues of a histone protein makes the
region of chromatin transcriptionally ___; addition of a(n) ___ group to certain lysine
residues makes the region of chromatin transcriptionally ___.
a. Acetyl, silent; methyl, active
b. Methyl, highly active; acetyl, active
c. Methyl, silent; phosphate, active
d. Methyl, silent; acetyl, active
e. Phosphate, silent; methyl, active - Answer d. Methyl, silent; acetyl, active
During termination, Rho acts as a ___.
a. Helicase
b. NTP hydrolase
c. Polymerase
d. Ligase
e. Single-stranded binding protein - Answer a. Helicase
What DNA sequence is found on the template strand at the termination of prokaryotic
transcription?
a. Series of CpG islands
b. Series of CG repeats followed by string of 10-12 U
c. Section of Z-DNA followed by repetitive CAT sequence
d. Series of TATA boxes
100% Correct |Verified Solutions
Which DNA strand is replicated exclusively in a discontinuous fashion?
a. Leading strand
b. Forward strand
c. Reverse strand
d. The strand read in 5' to 3' direction
e. Lagging strand - Answer e. Lagging strand
Which tumor suppressor gene is found to be mutated in at least half of all human
tumors?
a. p53
b. BRCA1
c. BRCA2
d. Retinoblastoma - Answer a. p53
What is the nucleophile in the DNA polymerase mechanism?
a. An oxygen anion on the -phosphate of the dNTP
b. The oxygen on the -phosphate of the dNTP
c. The 3' hydroxyl on the deoxyribose
d. The 5' hydroxyl on the deoxyribose
e. The oxygen on the -phosphate of the dNTP - Answer c. The 3' hydroxyl on the
deoxyribose
Synthesis of telomeres requires the enzyme ___, which is a type of ___.
,a. Topoisomerase, RNA-specific nuclease
b. Telomerase, helicase
c. Topoisomerase, ligase
d. Telomerase, reverse transcription - Answer d. Telomerase, reverse transcription
Besides the obvious role of keeping DNA in a single stranded state, what do single-
strand binding proteins do?
a. Prevent supercoiling
b. Aid in the formation of hairpin structures
c. Aid DNA polymerase with DNA binding
d. Protect single strand DNA from nucleases - Answer d. Protect single strand DNA from
nucleases
What is the purpose of DNA helicase?
a. Separation of double stranded DNA into single stranded DNA in front of DNA
polymerase
b. Removal of negative supercoiling to allow for replication
c. Conversion of single stranded DNA to double stranded DNA behind DNA polymerase
d. Removal of positive supercoiling to allow for replication - Answer a. Separation of
double stranded DNA into single stranded DNA in front of DNA polymerase
Histone proteins that bind to areas of DNA that are highly transcribed are often ___ on
___ residues.
a. Acetylated, histidine
b. Phosphorylated, serine
c. Phosphorylated, tyrosine
d. Methylated, lysine
,e. Acetylated, lysine - Answer e. Acetylated, lysine
What effect does a topoisomerase have on DNA?
a. Changed B-form DNA to A-form
b. Changes the supercoiling of DNA
c. Converts double stranded DNA to single stranded DNA
d. Denatures DNA - Answer b. Changes the supercoiling of DNA
Which type of DNA repair is used to remove and replace a single modified base that
cannot be converted back to a normal base by a direct repair process?
a. Mismatch repair
b. Base excision repair
c. Nucleotide excision repair
d. DNA photolyase - Answer b. Base excision repair
Which of the following is found in high concentrations in telomeres?
a. G
b. C
c. T
d. A
e. Pyrimidines - Answer a. G
Which of the following best describes the nucleic acid complex formed during DNA
polymerization?
a. One DNA-RNA hybrid and one single stranded DNA
b. One DNA-RNA hybrid with other DNA strand bound to an RNA molecules on RNA
polymerase
, c. There is no interaction between growing RNA and DNA
d. Two DNA-RNA hybrids since both DNA strands are transcribed simultaneously
e. None of the above - Answer a. One DNA-RNA hybrid and one single stranded DNA
Addition of a(n) ___ group to certain lysine residues of a histone protein makes the
region of chromatin transcriptionally ___; addition of a(n) ___ group to certain lysine
residues makes the region of chromatin transcriptionally ___.
a. Acetyl, silent; methyl, active
b. Methyl, highly active; acetyl, active
c. Methyl, silent; phosphate, active
d. Methyl, silent; acetyl, active
e. Phosphate, silent; methyl, active - Answer d. Methyl, silent; acetyl, active
During termination, Rho acts as a ___.
a. Helicase
b. NTP hydrolase
c. Polymerase
d. Ligase
e. Single-stranded binding protein - Answer a. Helicase
What DNA sequence is found on the template strand at the termination of prokaryotic
transcription?
a. Series of CpG islands
b. Series of CG repeats followed by string of 10-12 U
c. Section of Z-DNA followed by repetitive CAT sequence
d. Series of TATA boxes
