Chapter 8 part 2.
38.
A)
B)
C)
D)
What is +1?
The beginning of a cloned DNA fragment that contains a gene.
The first base of a gene to be transcribed. *
The first codon to be translated in a mRNA.
The first nucleotide of an exon.
39. Where or what is +10?
A) 10 nucleotides after the start of transcription. *
B) The first 10 nucleotides of an exon.
C) The first 10 nucleotides of a mRNA.
D) The first 10 codons of a gene.
40. Sigma binds both DNA and RNA polymerase,
A) True
B) False *
41. In prokaryotes transcription and translation occur in the same cellular
compartment
A) True *
B) False
42. A eukaryotic core promoter is a DNA sequence that specifies
A)
B)
C)
where transcription should start and how much transcription should occur.
where transcription should start and in which direction transcription should proceed.*
where transcription should start, in which direction transcription should proceed, and
how much transcription should occur.
43. Which entity is directly responsible for recognizing the position of a
bacterial promoter element?
A)
B)
C)
delta
RNA polymerase
sigma *
44. An RNA polymerase must finish transcribing a gene before another RNA
polymerase molecule can begin transcribing the gene.
A) True
B) False *
45. Transcription occurs in the ________ and translation occurs in the
__________ of prokaryotic cells.
A)
B)
C)
D)
nucleus, cytoplasm
cytoplasm, nucleus
nucleus, nucleus
cytoplasm, cytoplasm *
46. Which of these processes are coupled (linked) in prokaryotes but NOT in
eukaryotes?
A)
B)
C)
D)
transcription and translation *
replication and transcription
replication and translation
Replication, transcription, and translation are not separate in prokaryotes
47. In prokaryotes, the first nucleotide of the mRNA is the first nucleotide to be
transcribed.
A) True *
B) False
48. In prokaryotes, the end of the mRNA is produced when RNA polymerase
terminates transcription of the gene.
A) True *
B) False
49. In eukaryotes, the end of the mRNA is produced when RNA polymerase
terminates transcription of the gene.
A) True
B) False *
50. The 5' CAP of a mRNA is
A)
B)
C)
D)
added to the 5' end of the RNA as soon as this region is transcribed and enhances
the translatability of the mRNA. *
is encoded in some core promoter elements and lowers the translatability of the
mRNA
must be removed before the mRNA can be translated
is added to mRNAs immediately before they are degraded.
51. A mRNA loses its 5' CAP. Which of the following is the most likely
consequence?
A) The life of the mRNA will become longer.
B) The life of the mRNA will become very short. *
52. Processing of eukaryotic mRNA involves (choose all of the correct answers)
A) addition of a 5' methylated CAP
B) addition of a polyA tail
C) removal of introns
D) A and C
E) A, B, and C *
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53. The sequences within mRNA that are spliced out (removed) are called
A) extremes
B) exons
C) inclusions
D) introns *
54. In the modification of eukaryotic mRNA, a "cap" consisting of a/an
_________ and a tail consisting of _______ are usually added to the
transcript.
A)
B)
C)
D)
acetyl group, multiple cytosines
multiple guanines, methyl group
multiple thymines, acetyl group
methylated guanylate residue, multiple adenines *
55. Which of the following are features of a 5'-CAP? Please choose all of the
correct answers.
A) It is encoded in the genome by the sequence GCCAGG.
B) It is a 7-methyl-guanylate reside that is attached to the first nucleotide of a
mRNA. *
C) This structure is attached to the mRNA by a 5' to 5' phosphoester bond. *
D) A and B
E) B and C
56. The presence of the 5' CAP does what?
A) Enhances translatability of the mRNA.
B) Increases the efficiency of mRNA splicing.
C) Increases the efficiency of translation initiation of the mRNA.
D) Protects the mRNA from degradation.
E) All of the above *
57. Where is a 5' CAP found?
A) At the beginning of prokaryotic mRNA molecules.
B) At the beginning of eukaryotic mRNA molecules. *
58. How is the 3' end of the mRNA produced in eukaryotes
A) It is the last base to be transcribed when RNA polymerase is transcribing a
gene.
B) While RNA polymerase is transcribing the gene, a ribonuclease associated
with the polyadenylation complex cleaves the mRNA and releases it. *
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59. A 2' to 5' phosphodiester bond is produced
A) during capping
B) during polyadenylation
C) during splicing of pre-mRNA *
60. Ribonucleic acid differs from deoxyribonucleic acid in what way?
A) RNA has a hydroxy group at the 2' position of the ribose moiety and uses
uracil in place of thymine. *
B) RNA is missing a hydroxy group at both the 2' and 3' positions.
61. Short answer. What is the difference between RNA and DNA?
This is for preparation for the exam. It will not be answered here.
62. Short answer. What is polyadenylation?
This is for preparation for the exam. It will not be answered here.
63. Short answer. Describe alternative mRNA processing.
This is for preparation for the exam. It will not be answered here.
64. Short answer. How would you identify the introns in a gene?
This is for preparation for the exam. It will not be answered here. This might be difficult
for you.
This is actually a very difficult question for a Bio325 class at this point in the
course. Later it should become easier to answer. Were you able to do it?
65. Short answer. Explain RNA splicing using figures and text.
You do not need to name the ribonucleoprotein complexes that participate.
Your diagram/explanation should use the terms
5' splice site or donor site
3' splice site or acceptor site
branch point.
**Answer**
The 5' splice site/donor is the pGU between exon 1 and GU.
the 3' splice site/acceptor is the AGp before exon 2.
In addition to the cartoon below they need to identify the OH on the A as a 2' hydroxy that is
found on the branch point. They should also note that the reaction is a two-step
transesterification.
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2'OH on the branch point
transesterification
They don't have to include these 2!
bases. Instead they they could call it the!
3' splice site or the acceptor site.
OH
Exon 1 pGU-----------A---------------AGp Exon2
intron
They don't have to include these!
bases. Instead they could!
call the 1st one the 5' splice site or the!
donor site.
transesterification
Exon 1-OH
Exon 1-p-Exon 2
UG
p
A---------------AGp Exon2
UG
p
A---------------OH
Lariat is degraded
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