Unit 4 iClicker questions

What percentage of the human genome do you think codes for proteins? A. Less than 2% B. 10% C. 20% D. 50% E. 80%

A. Less than 2%

Which of the following would not typically cause a proto-oncogene to become an oncogene? A. gene repression B. translocation C. amplification D. point mutation

A. gene repression

Say each of a group of E. coli bacterial cells has a mutation in its lac operon. Which of the following mutations would make it impossible for the cell to metabolize lactose? A. mutation in lac Z (b -galactosidase gene) B.mutation in lac I (cannot bind to operator) C. mutation in operator (cannot bind to repressor) D. mutation in lac I (cannot bind to inducer)

A. mutation in lac Z (b -galactosidase gene)

An mRNA reads 5'- AUGUUAUAACCCUCA-3' What would the cell translate that as? A.Met-Leu B.Met-Leu-Pro-Ser C.Pro-Leu-Met D.Met-Leu-Asn-Pro-Ser E.Leu-Met

A.Met-Leu

When a mutation caused by a nucleotide pair insertion occurs in a protein coding region of a gene, which of the following effects can not occur? A.silent B.frameshift C.missense D.nonsense E.All are possible

A.silent

Say the rate of transcription for a gene is found to be affected by a mutation. Based on what you have learned in this unit, where would you expect the mutation to appear on the DNA? A) In an intron associated with the gene B) In the promotor for the gene C) In a splice site for the gene D) In the rRNA of the ribosomes translating the gene E) In the exon of the gene

B) In the promotor for the gene

An mRNA that is being produced is built from the ________. A) coding strand in both bacteria and eukaryotes B) template strand in both bacteria and eukaryotes C) coding strand in bacteria and the template strand in eukaryotes D) template strand in bacteria and the coding strand in eukaryotes E) coding or template strand in both bacteria and eukaryotes depending upon the species

B) template strand in both bacteria and eukaryotes

The coding strand of a portion of a gene reads 5ʹ ACTGGTTCA. What will be the sequence of the resulting transcript for this portion? A. 5ʹ UGACCAAGU B. 5ʹ ACUGGUUCA C. 5ʹ UGAACCAGU D. 5ʹ ACUUGGUC

B. 5ʹ ACUGGUUCA

If a checkpoint arrests the cell cycle permanently, what fate you think would be most likely for that cell? A. The cell will eventually just continue through the cell cycle. B. If the causes of cell cycle arrest can't be fix by the cell, the cell will die. C. The cell reverts to G0. D. A and C E. B and C

B. If the causes of cell cycle arrest can't be fix by the cell, the cell will die.

For any given gene, can transcription use either strand as the template strand by RNA polymerase? A. Yes B. No

B. No

Pair the following terms by their physical binding with each other: Promoter, operator, RNA polymerase, repressor protein. A. RNA polymerase with repressor protein, promoter with operator B. RNA polymerase with promoter; repressor protein with operator C. RNA polymerase with operator; repressor protein with promoter

B. RNA polymerase with promoter; repressor protein with operator

When tryptophan (an amino acid) is present in the external medium, the bacterium E. coli can absorb the tryptophan and does not need to make this amino acid. Which of the following is true when there is no tryptophan in the medium? A. The repressor is active and binds to the operator. B. The repressor is inactive, and RNA polymerase moves through the operator. C. The operator is bound, and mRNA is made. D. Genes are inactive. E. The corepressor binds to the repressor.

B. The repressor is inactive, and RNA polymerase moves through the operator.

Consider the diagram below, in which red strands are DNA and orange strands are potential RNA transcripts. Noting the orientation of the promoter, which letter(s) could represent proper transcripts? A. W B. Y C. Z D. Y and Z

B. Y

When a mutation caused by a nucleotide pair substitution occurs in a protein coding region of a gene, which of the following effects can not occur? A. silent B. frameshift C. missense D. nonsense E. All are possible

B. frameshift

If a DNA template strand has a sequence of 3ʹTACAATGTAGCC5ʹ, the RNA produced from it will be which sequence? A) 3ʹ TACAATGTAGCC 5ʹ B) 5ʹ ATGTTACATCGG 3ʹ C) 5ʹ AUGUUACAUCGG 3' D) 3ʹ AUGUUACAUCGG 5ʹ E) 3ʹ ATGTTACATCGG

C) 5ʹ AUGUUACAUCGG 3'

The following mRNA transcript would result in which polypeptide sequence? 5ʹ-ACUUU CACCU CAUGU UUUUA UCCUC CACUC CUUGA -3' A)Thr-Phe-Thr B)Phe-Leu-Ser-Ser-Thr-Pro C) Met-Phe-Leu-Ser-Ser-Thr-Pro D)Thr-Phe-Thr-Phe-Leu-Ser-Ser-Thr-Pro E) Met-Phe-Leu-Ser-Ser

C) Met-Phe-Leu-Ser-Ser-Thr-Pro

What is the function of the poly A tail? A)The poly A tail is required for the termination of transcription, it is recognized by the release factor proteins B)The poly A tail serves as a termination sequence for RNA polymerase III. C) The poly A tail increases mRNA stability in eukaryotes. D) The poly A tail increases mRNA stability in prokaryotes. E)The poly A tail increases mRNA stability in prokaryotes and eukaryotes

C) The poly A tail increases mRNA stability in eukaryotes.

Which of the following is NOT true of small effector molecules? A) They can cause a conformational change in a regulatory protein. B) They can prevent a repressor from binding a gene region. C) They can regulate gene transcription by binding to DNA. D) They can regulate gene transcription by binding a regulatory protein. E) All of the above are true

C) They can regulate gene transcription by binding to DNA.

Wild type bread mold can grow in a minimal medium without supplements, while certain mutated strains can only grow in a minimal medium that is supplemented with specific intermediates. See the figure below for an overview of the arginine biosynthetic pathway. A strain that can grow in a minimal medium containing arginine, but NOT in minimal media containing citrulline nor in minimal media containing ornithine would have a mutation in the gene that encodes for ________ A) enzyme 1. B) enzyme 2. C) enzyme 3. D) both enzymes 1 and 3. E) both enzymes 2 and 3

C) enzyme 3.

An mRNA sequence reads 5ʹ-AUA AUG GGC ACU CAU ACU UAA-3ʹ. How many distinct types of aminoacyl-tRNA synthetase are required to translate the mRNA sequence? A) two B) three C) four D) five E) six

C) four

Imagine an E. coli cell with a mutation that renders its trp repressor protein completely inactive. Which of the following would be true of that cell? A. It synthesizes tryptophan only when tryptophan is absent. B. It never synthesizes tryptophan. C. It always synthesizes tryptophan. D. It synthesizes tryptophan only when tryptophan is present

C. It always synthesizes tryptophan.

Say there was a mutation in the DNA sequence that damaged the enhancer regulatory element in a eukaryotic gene promoter, how would this affect the transcription of the gene? A. The transcriptional start sight would be shifted B. The TATA box would be non- functional C. The rate of transcription would be very low D. The promoter would signal early termination E. Transcription would be inaccurate

C. The rate of transcription would be very low

An aminoacyl tRNA synthase Valine is mutated so that it now attaches the amino acid glycine to the tRNA Valine instead of valine. What do you think this will cause to happen at translation? A. There will be glycines at all valine positions and valines at all glycine positions. B. There will be valines at all glycine positions and glycines at all valine positions. C. There will be glycines at all glycine positions and at all valine positions. D. There will be valines at all glycine positions and at all valine positions. E. There will be no translation

C. There will be glycines at all glycine positions and at all valine positions.

Which of the following statements correctly describes tumor-suppressor genes? A. They are frequently over expressed in cancerous cells. B. They are cancer-causing genes introduced into cells by viruses. C. They can encode proteins that promote DNA repair or surface adhesion of the cell. D. They can encode proteins that stop DNA repair. E. They destroy cancer cells

C. They can encode proteins that promote DNA repair or surface adhesion of the cell.

When is the lac operon optimally expressed? A. in the absence of both lactose and glucose B. in the absence of lactose and the presence of glucose C. in the presence of lactose and the absence of glucose D. in the presence of both lactose and glucose E. None of the above

C. in the presence of lactose and the absence of glucose

Which of the following statements about RNA polymerase in bacteria is incorrect? A) It binds the promoter region of a gene. B) It is bound to a sigma factor during initiation of transcription. C) It synthesizes RNA. D) It catalyzes the addition of nucleotides to the 5ʹend of a growing RNA strand. E) It dissociates from the DNA at the terminator

D) It catalyzes the addition of nucleotides to the 5ʹend of a growing RNA strand.

What type of regulatory transcription factor binds DNA and increases transcription of a gene? A) a repressor exerting negative control B) a repressor exerting positive control C) an activator exerting negative control D) an activator exerting positive control E) a combination of both a repressor and activator exerting negative control

D) an activator exerting positive control

Which of the following sequences of mRNA codes for five amino acids, with the correct punctuation and polarity? A.3'AUGUGCCCUCGAUUUUGACGG-5' B.3'AAUACUGCGGCUGUACCGGAG-5' C.5'-AUGCCCUGGUGAUAAUCC- 3' D.5'CUGAUGCGUGAAAGAUAUUAG-3' E. None of the above

D.5'CUGAUGCGUGAAAGAUAUUAG-3'

What is the 5ʹ→ 3ʹ sequence on the anticodon of the methionine (Met) tRNA? A.AUG B.GUA C.UAC D.CAU

D.CAU

If a DNA coding strand has a sequence of 3ʹ TACAATGTAGCC 5ʹ, the RNA produced would have what sequence? A) 3ʹ TACAATGTAGCC 5ʹ B) 3ʹ CCATGTTACATC 5ʹ C)5ʹ AUGUUACAUCGG 3' D)5ʹUACAAUGUAGCC 3' E) 5ʹ CCGAUGUAACAU 3'

E) 5ʹ CCGAUGUAACAU 3'

A researcher determined that a strain of E. coli is producing a shortened version of a protein required for glucose metabolism. What type of mutation could be responsible for this shorter than normal protein? A) missense mutation B) silent mutation C) sense mutation D) frameshift mutation E) nonsense mutation

E) nonsense mutation

Which of the following may be involved in combinatorial control of eukaryotic gene expression? A. Activator proteins B. Suppressor proteins C. DNA methylation D. Alteration of chromatin structure E. All of the above

E. All of the above

The process of transcription and translation are collectively known as... A. RNA processing B. Gene duplication C. protein synthesis D. DNA synthesis E. Gene expression

E. Gene expression