Question 1

When the ribosome reaches a stop codon on the mRNA,no corresponding tRNA enters the A site.If the translation reaction were to be experimentally stopped at this point,which of the following sets of structures would you be able to isolate from the cell?

Accepted Answer

A)  an assembled ribosome with a polypeptide attached to the tRNA in the P site
B)  separated ribosomal subunits,a polypeptide,and free tRNA
C)  an assembled ribosome with a separated polypeptide
D)  separated ribosomal subunits with a polypeptide attached to the tRNA

Question 2

Which of the following is not true of a codon?

Accepted Answer

A)  It may code for the same amino acid as another codon.
B)  It never codes for more than one amino acid.
C)  It extends from one end of a tRNA molecule.
D)  It is the basic unit of the genetic code.

Question 3

In the 1920s,Hermann Muller discovered that X-rays caused genetic changes in the fruit fly Drosophila.In a related series of experiments in the 1940s,other scientists discovered that other types of chemicals have a similar effect.A new chemical food additive is developed by a cereal manufacturer.Why is it necessary to test for its ability to cause 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 chance that it might cause mutations.

Question 4

Which of the following types of mutation,resulting in an error in the mRNA just after the 5ʹ AUG start codon,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

Question 5

-What type of bonding is responsible for maintaining the shape of the tRNA molecule in the figure above?

Accepted Answer

A)  covalent bonding between sulfur atoms
B)  ionic bonding between phosphates
C)  hydrogen bonding between base pairs
D)  van der Waals interactions between hydrogen atoms

Question 6

In eukaryotes there are several different types of RNA polymerase.Which type is involved in transcription of mRNA known as pre-mRNA?

Accepted Answer

A)  ligase
B)  RNA polymerase I
C)  RNA polymerase II
D)  RNA polymerase III

Question 7

How do small RNAs in the spliceosome initiate the splicing of the pre-mRNA?

Accepted Answer

A)  by base pairing to the exons on each side of the intron
B)  by binding to the 3'end of the pre-mRNA and removing the poly-A tail
C)  by base pairing to specific sites along the intron
D)  by base pairing to sites on both the intron and nearby exons

Question 8

Transcription in eukaryotes requires which of the following in addition to RNA polymerase?

Accepted Answer

A)  the protein product of the promoter
B)  start and stop codons
C)  ribosomes and tRNA
D)  several transcription factors

Question 9

The "universal" genetic code is now known to have exceptions.Evidence for this can be found if which of the following statements is true?

Accepted Answer

A)  if UGA,usually a stop codon,is found to code for an amino acid such as tryptophan (usually coded for by UGG only) 
B)  if one stop codon,such as UGA,is found to have the same effect on translation as another stop codon,such as UAA
C)  if prokaryotic organisms are able to translate a eukaryotic mRNA and produce the same polypeptide
D)  if several codons are found to translate to the same amino acid,such as serine

Question 10

Which of the following is a function of a poly-A tail in mRNA?

Accepted Answer

A)  It adds the modified guanine to the 3' end of the mRNA.
B)  It indicates the site of translational termination.
C)  It is a sequence that codes for the binding of RNA polymerase to the DNA.
D)  It helps protect the mRNA from degradation by hydrolytic enzymes.

Question 11

-Examine the table of codons in the figure above.A possible sequence of nucleotides in the template strand of DNA that would code for the polypeptide sequence phe-leu-ile-val would be

Accepted Answer

A)  5'-TTG-CTA-CAG-TAG-3'.
B)  3'-AAC-GAC-GUC-AUA-5'.
C)  5'-AUG-CTG-CAG-TAT-3'.
D)  3'-AAA-GAA-TAA-CAA-5'.

Question 12

Which of the following events in translation is the first to occur in eukaryotes?

Accepted Answer

A)  elongation of the polypeptide
B)  base pairing of activated methionine-tRNA to AUG of the messenger RNA
C)  binding of the larger ribosomal subunit to smaller ribosomal subunits
D)  the small subunit of the ribosome recognizing and attaching to the 5' cap of mRNA

Question 13

During the process of alternative RNA splicing,where on a pre-mRNA transcript does a spliceosome bind?

Accepted Answer

A)  to the exons
B)  to the 5' untranslated region
C)  to the 3' untranslated region
D)  on certain sequences of an intron

Question 14

In comparing DNA replication with RNA transcription in the same cell,which of the following is true only of replication?

Accepted Answer

A)  It uses RNA polymerase.
B)  It makes a new molecule from its 5' end to its 3' end.
C)  The process is extremely fast once it is initiated.
D)  The entire template molecule is represented in the product.

Question 15

A part of the promoter,called the TATA box,is said to be highly conserved in many different organisms through evolution.Which of the following correctly describes why this is the case?

Accepted Answer

A)  The sequence evolves very rapidly.
B)  The sequence does not mutate.
C)  Any mutation in the sequence is selected against.
D)  The sequence is found in many but not all promoters.

Question 16

Which of the following mutations would be most likely to have a harmful effect on an organism?

Accepted Answer

A)  a deletion of three nucleotides near the middle of a gene
B)  a single nucleotide deletion in the middle of an intron
C)  a single nucleotide deletion near the end of the coding sequence
D)  a single nucleotide insertion downstream of,and close to,the start of the coding sequence

Question 17

In eukaryotic cells,transcription cannot begin until

Accepted Answer

A)  the two DNA strands have completely separated and exposed the promoter.
B)  several transcription factors have bound to the promoter.
C)  the 5' caps are removed from the mRNA.
D)  the DNA introns are removed from the template.

Question 18

A eukaryotic mutation upstream of a particular gene has been identified that changes the sequence of the TATA box to GATA.How would you predict that this mutation would affect the transcription of this gene?

Accepted Answer

A)  Transcription would proceed normally.
B)  Transcription factors would bind to the start point in the promoter region.
C)  Transcription factor binding would be reduced or eliminated,and transcription of the gene would decrease dramatically.
D)  Transcription factors would bind in the middle of the gene sequence and transcribe the gene from that point.

Question 19

The genetic code is essentially the same for all organisms.Based on this information,one can logically assume which of the following statements to be correct?

Accepted Answer

A)  A gene from an organism can theoretically be expressed by any other organism.
B)  Gene expression differs considerably in different organisms.
C)  DNA was the first genetic material.
D)  The same codons in different organisms translate into the different amino acids.

Question 20

Accuracy in the translation of mRNA into the sequence of amino acids in a polypeptide depends on specificity in which of the following characteristics?

Accepted Answer

A)  binding of ribosomes to mRNA
B)  shape of the A and P sites of ribosomes
C)  attachment of amino acids to tRNAs
D)  bonding of the anticodon to the codon and the attachment of amino acids to tRNAs

Exam 14: Gene Expression: From Gene to Protein

Transcription in eukaryotes requires which of the following in addition to RNA polymerase?

Correct Answer
verified

Which of the following is a function of a poly-A tail in mRNA?

Correct Answer
verified

In eukaryotes there are several different types of RNA polymerase.Which type is involved in transcription of mRNA known as pre-mRNA?

Correct Answer
verified

Accuracy in the translation of mRNA into the sequence of amino acids in a polypeptide depends on specificity in which of the following characteristics?

Correct Answer
verified

Which of the following types of mutation,resulting in an error in the mRNA just after the 5ʹ AUG start codon,is likely to have the most serious effect on the polypeptide product?

Correct Answer
verified

-Examine the table of codons in the figure above.A possible sequence of nucleotides in the template strand of DNA that would code for the polypeptide sequence phe-leu-ile-val would be

Correct Answer
verified

In eukaryotic cells,transcription cannot begin until

Correct Answer
verified

-What type of bonding is responsible for maintaining the shape of the tRNA molecule in the figure above?

Correct Answer
verified

During the process of alternative RNA splicing,where on a pre-mRNA transcript does a spliceosome bind?

Correct Answer
verified

Which of the following is not true of a codon?

Correct Answer
verified

How do small RNAs in the spliceosome initiate the splicing of the pre-mRNA?

Correct Answer
verified

The "universal" genetic code is now known to have exceptions.Evidence for this can be found if which of the following statements is true?

Correct Answer
verified

A eukaryotic mutation upstream of a particular gene has been identified that changes the sequence of the TATA box to GATA.How would you predict that this mutation would affect the transcription of this gene?

Correct Answer
verified

Correct Answer
verified

Which of the following events in translation is the first to occur in eukaryotes?

Correct Answer
verified

When the ribosome reaches a stop codon on the mRNA,no corresponding tRNA enters the A site.If the translation reaction were to be experimentally stopped at this point,which of the following sets of structures would you be able to isolate from the cell?

Correct Answer
verified

In comparing DNA replication with RNA transcription in the same cell,which of the following is true only of replication?

Correct Answer
verified

Which of the following mutations would be most likely to have a harmful effect on an organism?

Correct Answer
verified

A part of the promoter,called the TATA box,is said to be highly conserved in many different organisms through evolution.Which of the following correctly describes why this is the case?

Correct Answer
verified

The genetic code is essentially the same for all organisms.Based on this information,one can logically assume which of the following statements to be correct?

Correct Answer
verified

Exam 14: Gene Expression: From Gene to Protein

Transcription in eukaryotes requires which of the following in addition to RNA polymerase?

Correct AnswerverifiedShow Answer

Which of the following is a function of a poly-A tail in mRNA?

Correct AnswerverifiedShow Answer

In eukaryotes there are several different types of RNA polymerase.Which type is involved in transcription of mRNA known as pre-mRNA?

Correct AnswerverifiedShow Answer

Accuracy in the translation of mRNA into the sequence of amino acids in a polypeptide depends on specificity in which of the following characteristics?

Correct AnswerverifiedShow Answer

Which of the following types of mutation,resulting in an error in the mRNA just after the 5ʹ AUG start codon,is likely to have the most serious effect on the polypeptide product?

Correct AnswerverifiedShow Answer

-Examine the table of codons in the figure above.A possible sequence of nucleotides in the template strand of DNA that would code for the polypeptide sequence phe-leu-ile-val would be

Correct AnswerverifiedShow Answer

In eukaryotic cells,transcription cannot begin until

Correct AnswerverifiedShow Answer

-What type of bonding is responsible for maintaining the shape of the tRNA molecule in the figure above?

Correct AnswerverifiedShow Answer

During the process of alternative RNA splicing,where on a pre-mRNA transcript does a spliceosome bind?

Correct AnswerverifiedShow Answer

Which of the following is not true of a codon?

Correct AnswerverifiedShow Answer

How do small RNAs in the spliceosome initiate the splicing of the pre-mRNA?

Correct AnswerverifiedShow Answer

The "universal" genetic code is now known to have exceptions.Evidence for this can be found if which of the following statements is true?

Correct AnswerverifiedShow Answer

A eukaryotic mutation upstream of a particular gene has been identified that changes the sequence of the TATA box to GATA.How would you predict that this mutation would affect the transcription of this gene?

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

Which of the following events in translation is the first to occur in eukaryotes?

Correct AnswerverifiedShow Answer

When the ribosome reaches a stop codon on the mRNA,no corresponding tRNA enters the A site.If the translation reaction were to be experimentally stopped at this point,which of the following sets of structures would you be able to isolate from the cell?

Correct AnswerverifiedShow Answer

In comparing DNA replication with RNA transcription in the same cell,which of the following is true only of replication?

Correct AnswerverifiedShow Answer

Which of the following mutations would be most likely to have a harmful effect on an organism?

Correct AnswerverifiedShow Answer

A part of the promoter,called the TATA box,is said to be highly conserved in many different organisms through evolution.Which of the following correctly describes why this is the case?

Correct AnswerverifiedShow Answer

The genetic code is essentially the same for all organisms.Based on this information,one can logically assume which of the following statements to be correct?

Correct AnswerverifiedShow Answer

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified