BIOL 2321 UNIT 2 EXAM PRACTICE
QUESTIONS AND ANSWERS
A particular animal virus requires the use of DNA polymerase from its host (since it does
not possess its own DNA polymerase enzyme. Which of the following assumptions in A-
D would likely be correct regarding this virus?
A) This virus could not be a retrovirus
B) It could be a (-) ss RNA virus
C) It could be a (+) ss RNA virus
D) The virus life cycle very likely includes going to the host cell nucleus
E) All of A-D are correct assumptions - Correct Answers -D) The virus life cycle very
likely includes going to the host cell nucleus
Which statement among A-C is false concerning the M13 filamentous bacteriophage?
A) It can form a prophage
B) It does not kill the host cell
C) Because of the life cycle it possesses, it can generally always be sure to have a host
cell(s) to infect
D) None of A-C is false; all are true statements - Correct Answers -A) It can form a
prophage
The CRISPR system of bacteria:
A) Is an operon consisting of several genes.
B) Is a type of bacterial immune system to defend against viruses
C) Facilitates the horizontal transfer of genes
D) Allows a prophage to form
E) All are applicable to the CRISPR system of bacteria - Correct Answers -B) Is a type
of bacterial immune system of defend against viruses
Which of the following is false regarding all types of viruses:
A) They all have either RNA or DNA
B) They all have a coat of capsid proteins surrounding their nucleic acid
C) They all require a host in order to form new viral particles
D) While outside of the host cell, all viruses can replicate their DNA or RNA
E) None of A-D are false; all true statements - Correct Answers -D) While outside of the
host cell, all viruses can replicate their DNA or RNA
, Which statement among A-D is false regarding animal viral infections?
A) Uncoating refers to the process of viral exit from the host cell
B) Depending on the virus type, assembly of viruses may occur in the nucleus or
cytoplasm
C) Budding is a mechanism of virus exit that leads to the acquisition of the envelope
around the viral particles
D) Endosome formation is a mechanism that allows for the viral genome to be freed
from the capsid
E) None of A-D are false - Correct Answers -A) Uncoating refers to the process of viral
exit from the host cell
Which of the follow directly relates to viral tropism?
A) The different types of cells/tissues the virus can infect in a host
B) Recognition of protein/glycoprotein receptors on the surface of the host cell(s)
C) The mode of entry of the virus
D) Capsid type of the virus
E) Two of the above are correct - Correct Answers -E) Two of the above are correct
(both A and B)
Which of the following is characteristic of the lytic cycle?
A) Many bacterial cells containing viral DNA are produced
B) Viral DNA is incorporated into the host genome
C) The viral genome replicates without destroying the host
D) A large number of phages are released at a time
E) None of the above is correct - Correct Answers -D) A large number of phages are
released at a time
Antisense RNAs DO NOT
A) occur in protein coding genes
B) affect expression of several protein coding genes in a cell
C) bind to mRNA
D) act as a translational control mechanism - Correct Answers -B) affect expression of
several protein coding genes in a cell
Which statements is true regarding prions and viroids?
A) Viruses have capsids composed of protein, whereas viroids have no capsids
B) Prions are infectious proteins and lack nucleic acids
C) Viroids are comprised only of RNA
D) Prions can cause a degenerative neurological disease in humans and other
mammals, whereas viroids primarily affect plants
E) All are true - Correct Answers -E) All are true
QUESTIONS AND ANSWERS
A particular animal virus requires the use of DNA polymerase from its host (since it does
not possess its own DNA polymerase enzyme. Which of the following assumptions in A-
D would likely be correct regarding this virus?
A) This virus could not be a retrovirus
B) It could be a (-) ss RNA virus
C) It could be a (+) ss RNA virus
D) The virus life cycle very likely includes going to the host cell nucleus
E) All of A-D are correct assumptions - Correct Answers -D) The virus life cycle very
likely includes going to the host cell nucleus
Which statement among A-C is false concerning the M13 filamentous bacteriophage?
A) It can form a prophage
B) It does not kill the host cell
C) Because of the life cycle it possesses, it can generally always be sure to have a host
cell(s) to infect
D) None of A-C is false; all are true statements - Correct Answers -A) It can form a
prophage
The CRISPR system of bacteria:
A) Is an operon consisting of several genes.
B) Is a type of bacterial immune system to defend against viruses
C) Facilitates the horizontal transfer of genes
D) Allows a prophage to form
E) All are applicable to the CRISPR system of bacteria - Correct Answers -B) Is a type
of bacterial immune system of defend against viruses
Which of the following is false regarding all types of viruses:
A) They all have either RNA or DNA
B) They all have a coat of capsid proteins surrounding their nucleic acid
C) They all require a host in order to form new viral particles
D) While outside of the host cell, all viruses can replicate their DNA or RNA
E) None of A-D are false; all true statements - Correct Answers -D) While outside of the
host cell, all viruses can replicate their DNA or RNA
, Which statement among A-D is false regarding animal viral infections?
A) Uncoating refers to the process of viral exit from the host cell
B) Depending on the virus type, assembly of viruses may occur in the nucleus or
cytoplasm
C) Budding is a mechanism of virus exit that leads to the acquisition of the envelope
around the viral particles
D) Endosome formation is a mechanism that allows for the viral genome to be freed
from the capsid
E) None of A-D are false - Correct Answers -A) Uncoating refers to the process of viral
exit from the host cell
Which of the follow directly relates to viral tropism?
A) The different types of cells/tissues the virus can infect in a host
B) Recognition of protein/glycoprotein receptors on the surface of the host cell(s)
C) The mode of entry of the virus
D) Capsid type of the virus
E) Two of the above are correct - Correct Answers -E) Two of the above are correct
(both A and B)
Which of the following is characteristic of the lytic cycle?
A) Many bacterial cells containing viral DNA are produced
B) Viral DNA is incorporated into the host genome
C) The viral genome replicates without destroying the host
D) A large number of phages are released at a time
E) None of the above is correct - Correct Answers -D) A large number of phages are
released at a time
Antisense RNAs DO NOT
A) occur in protein coding genes
B) affect expression of several protein coding genes in a cell
C) bind to mRNA
D) act as a translational control mechanism - Correct Answers -B) affect expression of
several protein coding genes in a cell
Which statements is true regarding prions and viroids?
A) Viruses have capsids composed of protein, whereas viroids have no capsids
B) Prions are infectious proteins and lack nucleic acids
C) Viroids are comprised only of RNA
D) Prions can cause a degenerative neurological disease in humans and other
mammals, whereas viroids primarily affect plants
E) All are true - Correct Answers -E) All are true
