DNA/RNA/Translation Questions
5) How do nucleotides connect to adjacent nucleotides in the Watson-Crick model of DNA?
a) Via a covalent bond between the 3’ hydroxyl of one nucleotide and the 2’ deoxy of the other.
b) Via a hydrogen bond between the nitrogenous base of one nucleotide and the nitrogenous base
of the other.
c) Via a hydrogen bond between the nitrogenous base of one nucleotide and the 5’ phosphate of
the other.
d) Via a covalent bond between the 3’ hydroxyl of one nucleotide and the nitrogenous base of
the other.
e) Via a covalent bond between the 3’ hydroxyl of one nucleotide and the 5’ phosphate of the
other.
9) What is the first protein to bind to the oriC region of the DNA molecule to start the replication
process?
a) DNA polymerase
b) the primase
c) DnaA
d) gyrase
e) DnaI
10) After the DNA is unwound at the site of DNA replication initiation, what binds to the
unwound DNA to prevent it from reannealing?
a) DNA gyrase
b) single-stranded DNA binding protein
c) DnaA
d) DNA polymerase
e) DnaB
12) Which statement below is FALSE regarding replication of the bacterial chromosome?
a) Replication occurs in a bidirectional manner from the origin of replication.
b) The leading strand is replicated in the 5’ to 3’ direction and the lagging strand in the 3’ to 5’
direction.
c) The primase adds a short RNA primer to serve as a starting point for the DNA polymerase to
add new bases.
d) DNA replication is a semi-conservative process, where one strand serves as a template for the
synthesis of a complementary strand.
e) The incoming nucleotide triphosphate is covalently attached to the free 3’ hydroxyl.
18) Which of these best differentiates DNA and RNA?
a) RNA is single-stranded and DNA is double stranded.
b) RNA contains ribose and DNA contains deoxyribose.
c) RNA contains the base uracil in place of thymine, which is in DNA.
d) Both a and b are true.
e) a, b, and c are true.
22) For the initiation of transcription in bacteria, RNA polymerase binds to what region on the
gene?
a) promoter
b) operator
c) enhancer region
d) origin of replication
e) Shine-Dalgarno sequence
23) What is the sigma factor of the RNA polymerase holoenzyme responsible for?
a) initiation of transcription
b) recognition of the promoter region
c) transcription elongation
d) transcription termination
e) ribosome binding
25) In eukaryal cells, what does RNA polymerase II transcribe?
a) tRNA genes
b) small regulatory RNAs
c) the 5S and 18S rRNAs
d) mRNA genes
e) rRNAs genes
8) What is a codon?
a) Four bases on the mRNA that is read by the ribosome in the 3’ to 5’ direction.
b) Four bases on the mRNA that is read by the ribosome in the 5’ to 3’ direction.
c) Three bases on the mRNA that is read by the ribosome in the 3’ to 5’ direction.
d) Three bases on the mRNA that is read by the ribosome in the 5’ to 3’ direction.
e) Two bases on the mRNA that is read by the ribosome in the 5’ to 3’ direction.
29) Initiation of translation in bacteria starts with the binding of the 30S ribosomal subunit to the
mRNA molecule. The ribosomal binding site is nearer the _________ end of the mRNA
molecule and is called the ________.
a) 3’; Pribnow box
b) 3’; Shine-Dalgarno sequence
c) 3’; Rho sequence
d) 5’; Shine-Dalgarno sequence
e) 5’; Rho sequence
17.
A.
B.
C.
D.
E.
What is the role of sigma70 (70) in E. coli?
To
To
To
To
To
guide RNA polymerase to generic, housekeeping promoters
guide RNA polymerase to heat shock promoters
guide DNA polymerase to generic, housekeeping promoters
guide DNA polymerase to heat shock promoters
stop transcription at Shine-Dalgarno sequences
18.
The following codon encodes histidine in mRNA: 5’-CAU-3’.
What would
the sequence of the anti-codon be on the histidine-tRNA that decodes the
codon?
A.
B.
C.
D.
E.
20.
5’
5’
5’
5’
5’
5’-UGG-3’
5’-UAC-3’
5’-CAU-3’
5’-AUG-3’
5’-GAU-3’
Consider the following regions of DNA:
TATAATTG
CATAATCG
TATAATCG
TATAACCG
TAAAATCG
3’
3’
3’
3’
3’
What is their consensus sequence?
A.
B.
C.
D.
E.
22.
A.
B.
C.
D.
5’ ATATTAAC 3’
5’ TATAATTG 3’
5’ TATAATCG 3’
Consensus sequences apply to RNA only
Not enough information to tell
What is a promoter?
The binding site of RNA polymerase
The termination signal that stops transcription of a gene
The place where bacterial chromosome replication starts
A cluster of bacterial genes all transcribed from one promoter
E.
None of the above
23. Imagine that you found a isolated some mRNA that encodes for a single
protein that is able to catalyze the conversion of lead ions to gold ions.
You measure the length of the mRNA molecules and find that they are 900 bases
long. What can you say about the protein?
A.
B.
C.
D.
E.
25.
A.
B.
C.
D.
E.
That
That
That
That
None
the protein is
the protein is
the protein is
the protein is
of the above
300 amino
more that
less than
900 amino
acids long
300 amino acids long
300 amino acids long
acids long
Consider the molecule shown below, in what structure would it be found?
DNA
Ribosomes
mRNA
Two of the above
All of the above
26. Which of the following statements about the role of RNA primase during
prokaryotic DNA replication is true?
A.
B.
C.
D.
E.
It is required because RNA is the target of topoisomerase action
It is required because PolIII cannot begin nucleic acid polymerization
RNA is required to keep the DNA strands separated during replication
Two of the above are correct
Three of the above are correct
27. Ribosomes are directed to their proper position at the start of a
cistron by:
A. The start codon of the cistron
B. The promoter and sigma70
C. The Shine-Dalgarno sequence
D. Ribosomal 16S RNA
E. Two of the above are correct
29. The organism Leadtoau mutans has a large set of genes that are needed to
convert lead to gold. These genes, called the pbau genes, cover nearly 10,000
bp. You find that a single base pair change ANYWHERE in ANY of the pbau
genes allows the organism to convert graphite to diamond. If the mutation
rate in Leadtoau mutans is 10-10, how many bacteria in a tube containing 109
bacteria should be able to synthesize a pair of diamonds for your mother from
some old pencil stubs in your desk drawer?
A.
B.
C.
D.
E.
1
1010
10
1000
10-9
30. In which of the following statements is the word “polycistronic” used
correctly?
A. Jane gave Peter a sample of polycistronic RNA isolated from chimpanzee
blood
B. Peter gave Jane several polycistronic proteins in return for access to
her DNA
analysis software.
C. Clearly Claudius was the perpetrator. Polycistronic DNA, that was a
perfect
match to his, was found in the victim’s ear.
D. Susan patented a polycistronic RNA that encoded a set of proteins that
could be
used for removing ice from airplane wings.
31.
A.
B.
C.
D.
E.
Which of the following would be an example of a bacterial gene?
A piece of DNA encoding a protein
A piece of DNA encoding a rRNA
A piece of DNA encoding a tRNA
None of the above
All of the above
32. Consider the following piece of DNA. Which part of it is the very
oldest?
/
/
5’
TTAGATCTCGGATTACGTATTCGACGTAGCGGCTAGCTCTCGGCAGGATCGGCTCGAGAATCGGTTCAGGATCGGC
3’
3’
AATGGCTAGCCTAATGCATAAGCTGCATCGCCGATCGAGAGCCGTCCTAGCCGAGCTCTTAGCCAAGTCCTAGCCG
5’
/
/
methyl
methyl
A.
B.
The left end of the top strand
The right end of the top strand
C.
D.
The left end of the bottom strand
The right end of the bottom strand