BCH 361 ICLICKER QUESTIONS
WITH REVISED AND UPDATED
ANSWERS
A bacterium was found to have a defective DNAligase. Which aspect of DNA replication
would bemost affected by this?
A. Synthesis of leading strand
B. Synthesis of lagging strand
C. Both strands would be affected equally
D. It has no affect on DNA replication. - Answer-B. Synthesis of lagging strand
Which of the following should be the sequence of the template strand DNA if a mRNA
with the sequence 5'-UGCAGUA-3' is needed?
A. 5'-TGCAGTA-3'
B. 5'-ATGACGT-3'
C. 5'-TACTGCA-3'
D. 5'-ACGTCAT-3' - Answer-C. 5'-TACTGCA-3'
Which of the following cannot be done by a RNA polymerase?
A. Start its own chain. (self-priming)
B. Denature the DNA double helix to create the"bubble".
C. Unwind DNA to relief overwinding.
D. Extend a RNA chain at the 3' end. - Answer-C. Unwind DNA to relief overwinding.
σ factors are involved in transcription initiation. Which of the following statements istrue?
A. RNA polymerase can initiate transcription without σ factors.
B. σ factors are also needed in the elongation phase of transcription.
C. σ factors are permanently attached to RNA polymerases.
D. σ factors are needed to recognize the promoter sequence. - Answer-D. σ factors are
needed to recognize the promoter sequence.
What's the role of inducer in the regulation of lac operon?
A. It binds to the operator, thus preventing transcription.
B. It binds to the repressor, preventing it from binding to the operator.
C. It is the DNA sequence recognized by RNA polymerase holo enzyme.
D. It helps the polymerase bind specifically to the promoter - Answer-B. It binds to the
repressor, preventing it from binding to the operator.
,Which of the following events is not unique to the eukaryotic transcription process?
A. 5' capping of mRNA.
B. Use of transcription factors to recognize promoter sequences.
C. Splicing of introns from mRNA.
D. Addition of poly-A tail. - Answer-B. Use of transcription factors to recognize promoter
sequences.
The mechanism of some nuclear receptor is analogous to the mechanism of lac operon
repressor. Which of the following comparisons between components in the two systems
is most appropriate?
'A. Steroid hormones in the nuclear receptor system play the same role as the repressor
in lac operon.
B. Nuclear receptors play the same role as the σ factor.C.
Steroid hormones play the role of lactose.
D. Nuclear receptors play the role of lactose. - Answer-C. Steroid hormones play the
role of lactose.
Which of the following is required in mRNA splicing?
A. rRNA.
B. tRNA.
C. snRNA.
D. No RNA is required. - Answer-C. snRNA.
What is the peptide sequence coded by the mRNA 5'-AGU
GAA CAG UGC-3'
A. Glu-Pro-Ala-Cys
B. Asn-Leu-Val-Ser
C. Ile-Val-Phe-Thr
D. Ser-Glu-Gln-Cys - Answer-D. Ser-Glu-Gln-Cys
During the translation of SARS-CoV-2 mRNA, the ribosome will shift the reading frame
by rereading one of the nucleotides. What is the peptide produced by the following
mRNA if the frame shift occurs?
5' UUU UUA AAC GGG UUU GC 3'
A. Phe-Leu-Asn-Gly-Phe-Ala
B. Phe-Leu-Asn-Arg-Val-Cys
C. Cys-Val-Arg-Asn-Leu-Phe
D. Ala-Phe-Gly-Asn-Leu-Phe - Answer-B. Phe-Leu-Asn-Arg-Val-Cys
What's wrong with the picture shown on the right?
A. Coding strand and non-coding strand are switched.
B. mRNA codons are wrong.
C. tRNA anti-codons are wrong.
, D. All of the above. - Answer-D. All of the above.
What is the function of aminoacyl-tRNA synthetases?
A. To attach amino acid to the 3' end of tRNAs.
B. To catalyze the transfer of amino acid from tRNA
to existing peptide chains in ribosome.
C. To deliver amino acids to the ribosome.
D. To attach amino acid to the 5' end of tRNAs. Translation II - Answer-A. To attach
amino acid to the 3' end of tRNAs.
What is always the first residue in a polypeptide synthesized by prokaryotic ribosome?
A. Glycine
B. Methionine
C. Formylmethionine
D. Leucine - Answer-C. Formylmethionine
Which protein recognizes the stop codon of a mRNA and terminate the translation?
A. EF-Tu
B. EF-G
C. IF-2
D. RF1 - Answer-D. RF1
Which of the following types of RNA is not required for translation?
A. mRNA
B. rRNA
C. snRNA
D. tRNA - Answer-C. snRNA
Which of the following can not be present when brewing alcoholic beverages?
A. Water
B. O2
C. Carbohydrate
D. Microbes - Answer-B. O2
How many intermediates in glycolysis contains the functional group aldehyde?
A. 0
B. 1
C. 2
D. 3 - Answer-B. 1
What is the effect of fructose 2,6-bisphosphate onglycolysis?
A. It stimulates muscle PFK
B. It inhibits liver pyruvate kinase
C. It stimulates liver PFK
WITH REVISED AND UPDATED
ANSWERS
A bacterium was found to have a defective DNAligase. Which aspect of DNA replication
would bemost affected by this?
A. Synthesis of leading strand
B. Synthesis of lagging strand
C. Both strands would be affected equally
D. It has no affect on DNA replication. - Answer-B. Synthesis of lagging strand
Which of the following should be the sequence of the template strand DNA if a mRNA
with the sequence 5'-UGCAGUA-3' is needed?
A. 5'-TGCAGTA-3'
B. 5'-ATGACGT-3'
C. 5'-TACTGCA-3'
D. 5'-ACGTCAT-3' - Answer-C. 5'-TACTGCA-3'
Which of the following cannot be done by a RNA polymerase?
A. Start its own chain. (self-priming)
B. Denature the DNA double helix to create the"bubble".
C. Unwind DNA to relief overwinding.
D. Extend a RNA chain at the 3' end. - Answer-C. Unwind DNA to relief overwinding.
σ factors are involved in transcription initiation. Which of the following statements istrue?
A. RNA polymerase can initiate transcription without σ factors.
B. σ factors are also needed in the elongation phase of transcription.
C. σ factors are permanently attached to RNA polymerases.
D. σ factors are needed to recognize the promoter sequence. - Answer-D. σ factors are
needed to recognize the promoter sequence.
What's the role of inducer in the regulation of lac operon?
A. It binds to the operator, thus preventing transcription.
B. It binds to the repressor, preventing it from binding to the operator.
C. It is the DNA sequence recognized by RNA polymerase holo enzyme.
D. It helps the polymerase bind specifically to the promoter - Answer-B. It binds to the
repressor, preventing it from binding to the operator.
,Which of the following events is not unique to the eukaryotic transcription process?
A. 5' capping of mRNA.
B. Use of transcription factors to recognize promoter sequences.
C. Splicing of introns from mRNA.
D. Addition of poly-A tail. - Answer-B. Use of transcription factors to recognize promoter
sequences.
The mechanism of some nuclear receptor is analogous to the mechanism of lac operon
repressor. Which of the following comparisons between components in the two systems
is most appropriate?
'A. Steroid hormones in the nuclear receptor system play the same role as the repressor
in lac operon.
B. Nuclear receptors play the same role as the σ factor.C.
Steroid hormones play the role of lactose.
D. Nuclear receptors play the role of lactose. - Answer-C. Steroid hormones play the
role of lactose.
Which of the following is required in mRNA splicing?
A. rRNA.
B. tRNA.
C. snRNA.
D. No RNA is required. - Answer-C. snRNA.
What is the peptide sequence coded by the mRNA 5'-AGU
GAA CAG UGC-3'
A. Glu-Pro-Ala-Cys
B. Asn-Leu-Val-Ser
C. Ile-Val-Phe-Thr
D. Ser-Glu-Gln-Cys - Answer-D. Ser-Glu-Gln-Cys
During the translation of SARS-CoV-2 mRNA, the ribosome will shift the reading frame
by rereading one of the nucleotides. What is the peptide produced by the following
mRNA if the frame shift occurs?
5' UUU UUA AAC GGG UUU GC 3'
A. Phe-Leu-Asn-Gly-Phe-Ala
B. Phe-Leu-Asn-Arg-Val-Cys
C. Cys-Val-Arg-Asn-Leu-Phe
D. Ala-Phe-Gly-Asn-Leu-Phe - Answer-B. Phe-Leu-Asn-Arg-Val-Cys
What's wrong with the picture shown on the right?
A. Coding strand and non-coding strand are switched.
B. mRNA codons are wrong.
C. tRNA anti-codons are wrong.
, D. All of the above. - Answer-D. All of the above.
What is the function of aminoacyl-tRNA synthetases?
A. To attach amino acid to the 3' end of tRNAs.
B. To catalyze the transfer of amino acid from tRNA
to existing peptide chains in ribosome.
C. To deliver amino acids to the ribosome.
D. To attach amino acid to the 5' end of tRNAs. Translation II - Answer-A. To attach
amino acid to the 3' end of tRNAs.
What is always the first residue in a polypeptide synthesized by prokaryotic ribosome?
A. Glycine
B. Methionine
C. Formylmethionine
D. Leucine - Answer-C. Formylmethionine
Which protein recognizes the stop codon of a mRNA and terminate the translation?
A. EF-Tu
B. EF-G
C. IF-2
D. RF1 - Answer-D. RF1
Which of the following types of RNA is not required for translation?
A. mRNA
B. rRNA
C. snRNA
D. tRNA - Answer-C. snRNA
Which of the following can not be present when brewing alcoholic beverages?
A. Water
B. O2
C. Carbohydrate
D. Microbes - Answer-B. O2
How many intermediates in glycolysis contains the functional group aldehyde?
A. 0
B. 1
C. 2
D. 3 - Answer-B. 1
What is the effect of fructose 2,6-bisphosphate onglycolysis?
A. It stimulates muscle PFK
B. It inhibits liver pyruvate kinase
C. It stimulates liver PFK
