Question 1

Use the following figure to answer the questions below.
 
-The figure represents tRNA that recognizes and binds a particular amino acid (in this instance, phenylalanine) . Which codon on the mRNA strand codes for this amino acid?

Accepted Answer

A)  UGG
B)  GUG
C)  GUA
D)  UUC
E)  CAUF) A) and E)
G) B) and D)

Question 2

In the 1920s, Muller discovered that X-rays caused mutation in Drosophila. In a related series of experiments in the 1940s, Charlotte Auerbach discovered that chemicals-she used nitrogen mustards-have a similar effect. A new chemical food additive is developed by a cereal manufacturer. Why do we test for its ability to induce mutation?

Accepted Answer

A)  We worry that it might cause mutation in cereal grain plants.
B)  We want to make sure that it does not emit radiation.
C)  We want to be sure that it increases the rate of mutation sufficiently.
D)  We want to prevent any increase in mutation frequency.
E)  We worry about its ability to cause infection.F) C) and E)
G) B) and D) D

Question 3

Use this representation to answer the following questions.
DNA template strand 5' ____________________________ 3'
DNA complementary strand 3' ____________________________ 5'
-Given the locally unwound double strand above, in which direction does the RNA polymerase move?

Accepted Answer

A)  3' → 5' along the template strand
B)  5' → 3' along the template strand
C)  3' → 5' along the complementary strand
D)  5' → 3' along the complementary strand
E)  5' → 3' along the double-stranded DNAF) A) and D)
G) None of the above

Question 4

Use the following model of a eukaryotic transcript to answer the next few questions.
5' UTR E₁ I₁ E₂ I₂ E₃ I₃ E₄ UTR 3'
-Which of the following is a useful feature of introns for this model?

Accepted Answer

A)  They are translated into small polypeptides.
B)  They become parts of snRNPs.
C)  Each intron has enzymatic properties.
D)  Introns allow exon shuffling.
E)  Introns protect exon structure.F) A) and E)
G) C) and D)

Question 5

Which small-scale mutation would be most likely to have a catastrophic effect on the functioning of a protein?

Accepted Answer

A)  a base substitution
B)  a base deletion near the start of a gene
C)  a base deletion near the end of the coding sequence, but not in the terminator codon
D)  deletion of three bases near the start of the coding sequence, but not in the initiator codon
E)  a base insertion near the end of the coding sequence, but not in the terminator codonF) C) and E)
G) B) and D)

Question 6

Changes in a single nucleotide pair within a gene is called

Accepted Answer

A)  substitution.
B)  translocation.
C)  point mutation.
D)  silent mutation.
E)  evolution.F) A) and B)
G) C) and D)

Question 7

Which of the following types of mutation, resulting in an error in the mRNA just after the AUG start of translation, is likely to have the most serious effect on the polypeptide product?

Accepted Answer

A)  a deletion of a codon
B)  a deletion of two nucleotides
C)  a substitution of the third nucleotide in an ACC codon
D)  a substitution of the first nucleotide of a GGG codon
E)  an insertion of a codonF) A) and B)
G) A) and E)

Question 8

The following questions refer to this figure of a simple metabolic pathway:
 
-If A, B, and C are all required for growth, a strain that is mutant for the gene-encoding enzyme A would be able to grow on which of the following media?

Accepted Answer

A)  minimal medium
B)  minimal medium supplemented with nutrient A only
C)  minimal medium supplemented with nutrient B only
D)  minimal medium supplemented with nutrient C only
E)  minimal medium supplemented with nutrients A and CF) B) and E)
G) A) and B)

Question 9

Use the following information to answer the questions below.
Yeast is capable of synthesizing the amino acids necessary for survival and can grow on minimal media or enriched media easily. In both conditions, the colonies have a cream colour. The production of adenine is regulated by two genes, ADE1 and ADE2. If either of these genes is defective, adenine cannot be synthesized and the colony will look red (as a result of accumulation of precursors) . A common undergraduate lab study is to irradiate yeast cells with ultra violet light from 2-5 sec up to 1-5 minutes, and see what will happen.
-If, after irradiating and growing cultures in enriched media, you see some red colonies, what is the easiest way to confirm that the phenotype observed is due to a lack of adenine metabolism?

Accepted Answer

A)  Grow them with and without adenine in the media.
B)  Grow them with and without the adenine precursor.
C)  You would have to see the DNA sequences.
D)  Look for the protein products and compare them to wild type.
E)  See if the colonies could survive with a higher dosage of UV irradiation.F) A) and B)
G) All of the above

Question 10

The following questions refer to this figure of a simple metabolic pathway:
 
-A mutation results in a defective enzyme A. Which of the following would be a consequence of that mutation?

Accepted Answer

A)  an accumulation of A and no production of B and C
B)  an accumulation of A and B and no production of C
C)  an accumulation of B and no production of A and C
D)  an accumulation of B and C and no production of A
E)  an accumulation of C and no production of A and BF) All of the above
G) A) and D)

Question 11

The following questions refer to this figure of a simple metabolic pathway:
 
-According to Beadle and Tatum"s hypothesis, how many genes are necessary for this pathway?

Accepted Answer

A)  0
B)  1
C)  2
D)  3
E)  It cannot be determined from the pathway.F) A) and B)
G) C) and D)

Question 12

Use the following figure to answer the questions below.
 
-The tRNA shown in the figure has its 3' end projecting beyond its 5' end. What will occur at this 3' end?

Accepted Answer

A)  The codon and anticodon complement one another.
B)  The amino acid binds covalently.
C)  The excess nucleotides (ACC
A)  will be cleaved off at the ribosome.
D)  The small and large subunits of the ribosome will attach to it.
E)  The 5' cap of the mRNA will become covalently bound.F) A) and C)
G) A) and E) B

Question 13

During splicing, which molecular component of the spliceosome catalyzes the excision reaction?

Accepted Answer

A)  protein
B)  DNA
C)  RNA
D)  lipid
E)  sugarF) All of the above
G) C) and D)

Question 14

Garrod's information about the enzyme alteration resulting in alkaptonuria led to further elucidation of the same pathway in humans. Phenylketonuria (PKU) occurs when another enzyme in the pathway is altered or missing, resulting in a failure of phenylalanine (phe) to be metabolized to another amino acid: tyrosine. Tyrosine is an earlier substrate in the pathway altered in alkaptonuria. How might PKU affect the presence or absence of alkaptonuria?

Accepted Answer

A)  It would have no effect, because PKU occurs several steps away in the pathway.
B)  It would have no effect, because tyrosine is also available from the diet.
C)  Anyone with PKU must also have alkaptonuria.
D)  Anyone with PKU is born with a predisposition to later alkaptonuria.
E)  Anyone with PKU has mild symptoms of alkaptonuria.F) A) and D)
G) C) and D)

Question 15

A particular triplet of bases in the coding sequence of DNA is AAA. The anticodon on the tRNA that binds the mRNA codon is

Accepted Answer

A)  TTT.
B)  UUA.
C)  UUU.
D)  AAA.
E)  either UAA or TAA, depending on first base wobble.F) A) and C)
G) B) and D)

Question 16

Which of the following does not occur in prokaryotic eukaryotic gene expression, but does in eukaryotic gene expression?

Accepted Answer

A)  mRNA, tRNA, and rRNA are transcribed.
B)  RNA polymerase binds to the promoter.
C)  A poly-A tail is added to the 3' end of an mRNA and a cap is added to the 5' end.
D)  Transcription can begin as soon as translation has begun even a little.
E)  RNA polymerase requires a primer to elongate the molecule.F) A) and B)
G) B) and C)

Question 17

A particular triplet of bases in the template strand of DNA is 5' AGT 3'. The corresponding codon for the mRNA transcribed is

Accepted Answer

A)  3' UCA 5'.
B)  3' UGA 5'.
C)  5' TCA 3'.
D)  3' ACU 5'.
E)  either UCA or TCA, depending on wobble in the first base.F) B) and D)
G) A) and C)

Question 18

If a nucleotide substitution switched a U for a C, such that the codon was read as CGC instead of CGU, what would the effect be?

Accepted Answer

A)  a misfolding of the protein
B)  an incomplete protein
C)  nothing, as the third nucleotide does not determine the amino acid used.
D)  nothing, since both these codons code for arginine
E)  it would initiate a tumourF) B) and C)
G) D) and E)

Question 19

A transcription unit that is 8000 nucleotides long may use 1200 nucleotides to make a protein consisting of approximately 400 amino acids. This is best explained by the fact that

Accepted Answer

A)  many noncoding stretches of nucleotides are present in mRNA.
B)  there is redundancy and ambiguity in the genetic code.
C)  many nucleotides are needed to code for each amino acid.
D)  nucleotides break off and are lost during the transcription process.
E)  there are termination exons near the beginning of mRNA.F) A) and D)
G) A) and E) A

Question 20

Suppose that exposure to a chemical mutagen results in a change in the sequence that alters the 5' end of intron 1 (I₁) . What might occur?

Accepted Answer

A)  loss of the gene product
B)  loss of E₁
C)  premature stop to the mRNA
D)  inclusion of I₁ in the mRNA
E)  exclusion of E₂F) C) and D)
G) A) and B)

Exam 17: From Gene to Protein

Use the following figure to answer the questions below. -The figure represents tRNA that recognizes and binds a particular amino acid (in this instance, phenylalanine) . Which codon on the mRNA strand codes for this amino acid?

Correct Answer
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Correct Answer
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D

Use this representation to answer the following questions. DNA template strand 5' 3' DNA complementary strand 3' 5' -Given the locally unwound double strand above, in which direction does the RNA polymerase move?

Correct Answer
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Use the following model of a eukaryotic transcript to answer the next few questions. 5' UTR E₁ I₁ E₂ I₂ E₃ I₃ E₄ UTR 3' -Which of the following is a useful feature of introns for this model?

Correct Answer
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Which small-scale mutation would be most likely to have a catastrophic effect on the functioning of a protein?

Correct Answer
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Changes in a single nucleotide pair within a gene is called

Correct Answer
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Which of the following types of mutation, resulting in an error in the mRNA just after the AUG start of translation, is likely to have the most serious effect on the polypeptide product?

Correct Answer
verified

The following questions refer to this figure of a simple metabolic pathway: -If A, B, and C are all required for growth, a strain that is mutant for the gene-encoding enzyme A would be able to grow on which of the following media?

Correct Answer
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Correct Answer
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The following questions refer to this figure of a simple metabolic pathway: -A mutation results in a defective enzyme A. Which of the following would be a consequence of that mutation?

Correct Answer
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The following questions refer to this figure of a simple metabolic pathway: -According to Beadle and Tatum"s hypothesis, how many genes are necessary for this pathway?

Correct Answer
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Use the following figure to answer the questions below. -The tRNA shown in the figure has its 3' end projecting beyond its 5' end. What will occur at this 3' end?

Correct Answer
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B

During splicing, which molecular component of the spliceosome catalyzes the excision reaction?

Correct Answer
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Correct Answer
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A particular triplet of bases in the coding sequence of DNA is AAA. The anticodon on the tRNA that binds the mRNA codon is

Correct Answer
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Which of the following does not occur in prokaryotic eukaryotic gene expression, but does in eukaryotic gene expression?

Correct Answer
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A particular triplet of bases in the template strand of DNA is 5' AGT 3'. The corresponding codon for the mRNA transcribed is

Correct Answer
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If a nucleotide substitution switched a U for a C, such that the codon was read as CGC instead of CGU, what would the effect be?

Correct Answer
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A transcription unit that is 8000 nucleotides long may use 1200 nucleotides to make a protein consisting of approximately 400 amino acids. This is best explained by the fact that

Correct Answer
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A

Suppose that exposure to a chemical mutagen results in a change in the sequence that alters the 5' end of intron 1 (I₁) . What might occur?

Correct Answer
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Exam 17: From Gene to Protein

Use the following figure to answer the questions below. -The figure represents tRNA that recognizes and binds a particular amino acid (in this instance, phenylalanine) . Which codon on the mRNA strand codes for this amino acid?

Correct AnswerverifiedShow Answer

Correct AnswerverifiedD

Use this representation to answer the following questions. DNA template strand 5' ____________________________ 3' DNA complementary strand 3' ____________________________ 5' -Given the locally unwound double strand above, in which direction does the RNA polymerase move?

Correct AnswerverifiedShow Answer

Use the following model of a eukaryotic transcript to answer the next few questions. 5' UTR E₁ I₁ E₂ I₂ E₃ I₃ E₄ UTR 3' -Which of the following is a useful feature of introns for this model?

Correct AnswerverifiedShow Answer

Which small-scale mutation would be most likely to have a catastrophic effect on the functioning of a protein?

Correct AnswerverifiedShow Answer

Changes in a single nucleotide pair within a gene is called

Correct AnswerverifiedShow Answer

Which of the following types of mutation, resulting in an error in the mRNA just after the AUG start of translation, is likely to have the most serious effect on the polypeptide product?

Correct AnswerverifiedShow Answer

The following questions refer to this figure of a simple metabolic pathway: -If A, B, and C are all required for growth, a strain that is mutant for the gene-encoding enzyme A would be able to grow on which of the following media?

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

The following questions refer to this figure of a simple metabolic pathway: -A mutation results in a defective enzyme A. Which of the following would be a consequence of that mutation?

Correct AnswerverifiedShow Answer

The following questions refer to this figure of a simple metabolic pathway: -According to Beadle and Tatum"s hypothesis, how many genes are necessary for this pathway?

Correct AnswerverifiedShow Answer

Use the following figure to answer the questions below. -The tRNA shown in the figure has its 3' end projecting beyond its 5' end. What will occur at this 3' end?

Correct AnswerverifiedB

During splicing, which molecular component of the spliceosome catalyzes the excision reaction?

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

A particular triplet of bases in the coding sequence of DNA is AAA. The anticodon on the tRNA that binds the mRNA codon is

Correct AnswerverifiedShow Answer

Which of the following does not occur in prokaryotic eukaryotic gene expression, but does in eukaryotic gene expression?

Correct AnswerverifiedShow Answer

A particular triplet of bases in the template strand of DNA is 5' AGT 3'. The corresponding codon for the mRNA transcribed is

Correct AnswerverifiedShow Answer

If a nucleotide substitution switched a U for a C, such that the codon was read as CGC instead of CGU, what would the effect be?

Correct AnswerverifiedShow Answer

A transcription unit that is 8000 nucleotides long may use 1200 nucleotides to make a protein consisting of approximately 400 amino acids. This is best explained by the fact that

Correct AnswerverifiedA

Suppose that exposure to a chemical mutagen results in a change in the sequence that alters the 5' end of intron 1 (I₁) . What might occur?

Correct AnswerverifiedShow Answer

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D

Use this representation to answer the following questions. DNA template strand 5' 3' DNA complementary strand 3' 5' -Given the locally unwound double strand above, in which direction does the RNA polymerase move?

Correct Answer
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B

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A

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