Question 1

The viral polymerase complex from the RNA phage Qb contains which of the following host cell proteins?

Accepted Answer

A)  Host Factor 
B)  S1 ribosomal protein 
C)  EF-Tu translational factor 
D)  EF-Ts translational factor 
E)  All of the above are part of the complex. 
A)  Host Factor 
B)  S1 ribosomal protein 
C)  EF-Tu translational factor 
D)  EF-Ts translational factor 
E)  All of the above are part of the complex.

Question 2

How is the structure of an RNA phage virion different from the structure of the virion of many dsDNA phages?

Accepted Answer

A)  They have much shorter tails than the DNA phages. 
B)  The heads do not use icosahedral symmetry. 
C)  The icosahedral head has a very large triangulation number. 
D)  They are solely composed of a helical nucleocapsid. 
E)  They lack the tail structure used to inject the genome into the host cell. 
A)  They have much shorter tails than the DNA phages. 
B)  The heads do not use icosahedral symmetry. 
C)  The icosahedral head has a very large triangulation number. 
D)  They are solely composed of a helical nucleocapsid. 
E)  They lack the tail structure used to inject the genome into the host cell.

Question 3

What is the function of Host Factor during the replication of the Qb RNA genome?

Accepted Answer

A)  It delays the folding of the RNA into its final secondary structure. 
B)  It makes the 3' end of the genome more accessible to the replicase enzyme. 
C)  It adds a non-template A nucleotide to the 5' end of the minus strand. 
D)  It facilitates binding of the replicase protein to the coat protein start codon. 
E)  It prevents binding of the replicase enzyme to the 5' end of the genome. 
A)  It delays the folding of the RNA into its final secondary structure. 
B)  It makes the 3' end of the genome more accessible to the replicase enzyme. 
C)  It adds a non-template A nucleotide to the 5' end of the minus strand. 
D)  It facilitates binding of the replicase protein to the coat protein start codon. 
E)  It prevents binding of the replicase enzyme to the 5' end of the genome.

Question 4

In the ssRNA phage Qb the synthesis of the plus strand RNA genome from the negative strand template does not require the ribosomal S1 protein.Which of the following explains why?

Accepted Answer

A)  The minus strand is shorter and takes less time to replicate 
B)  The minus strand lacks the secondary structure that prevents replication. 
C)  There is no competition between binding of the replicase enzyme and the ribosome. 
D)  The replicase enzyme is more processive when copying the minus strand. 
E)  The minus strand has a lower GC content than the plus strand. 
A)  The minus strand is shorter and takes less time to replicate 
B)  The minus strand lacks the secondary structure that prevents replication. 
C)  There is no competition between binding of the replicase enzyme and the ribosome. 
D)  The replicase enzyme is more processive when copying the minus strand. 
E)  The minus strand has a lower GC content than the plus strand.

Question 5

The RNA phages do not use a tail assembly to inject their genome through the cell wall of the host cell.How do they get their genome into the host cell?

Accepted Answer

The RNA phage can only infect male E.col

Question 6

Translational readthrough occasionally occurs in the coat protein gene of the ssRNA phage Qb.Which of the following describes this process?

Accepted Answer

A)  The stop codon (UG
A)  is read as a tryptophan codon (UGG). 
B)  The RNA-dependent RNA polymerase reads into the next gene. 
C)  The RNA-dependent RNA polymerase inserts an extra base in this gene. 
D)  The ribosome shifts back one base and reads a different reading frame. 
E)  The ribosome shifts forward one base and reads a different reading frame. 
A)  The stop codon (UG
A)  is read as a tryptophan codon (UGG). 
B)  The RNA-dependent RNA polymerase reads into the next gene. 
C)  The RNA-dependent RNA polymerase inserts an extra base in this gene. 
D)  The ribosome shifts back one base and reads a different reading frame. 
E)  The ribosome shifts forward one base and reads a different reading frame.

Exam 5: Single-Stranded RNA Bacteriophages

The viral polymerase complex from the RNA phage Qb contains which of the following host cell proteins?

How is the structure of an RNA phage virion different from the structure of the virion of many dsDNA phages?

What is the function of Host Factor during the replication of the Qb RNA genome?

In the ssRNA phage Qb the synthesis of the plus strand RNA genome from the negative strand template does not require the ribosomal S1 protein.Which of the following explains why?

The RNA phages do not use a tail assembly to inject their genome through the cell wall of the host cell.How do they get their genome into the host cell?

Translational readthrough occasionally occurs in the coat protein gene of the ssRNA phage Qb.Which of the following describes this process?

Introduction to Virology

Virus Structure and Assembly

Virus Classification: The World of Viruses

Virus Entry

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Bacteriophage

Bacteriophage Lambda

Viruses of Archaea

Cucumber Mosaic Virus

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