Question 1

The proteins on the external surface of viruses serve several important functions. Regarding these proteins, which one of the following statements is most accurate?

Accepted Answer

The proteins on the external surface of viruses are primarily antigens that elicit an immune response, leading to the formation of neutralizing antibodies.

Question 2

If a virus has an envelope, it is more easily inactivated by lipid solvents and detergents than viruses that do not have an envelope. Which one of the following viruses is the most sensitive to inactivation by lipid solvents and detergents?

Accepted Answer

The correct answer is D because coronaviruses have an envelope, which makes them more susceptible to inactivation by lipid solvents and detergents.

Question 3

All of the following is correct as regard viruses Except

Accepted Answer

Viruses cannot grow on artificial media as they require living host cells to replicate.

Question 4

Many viruses are highly specific regarding the type of cells they infect. Of the following, which one is the most important determinant of this specificity?

Accepted Answer

The surface glycoprotein is crucial for determining the specificity of viral infection as it interacts with specific receptors on the host cell surface, allowing the virus to attach and enter the cell.

Question 5

Your summer research project is to study the viruses that cause upper respiratory tract infections. You have isolated a virus from a patient's throat and find that its genome is RNA. Furthermore, you find that the genome is the complement of viral mRNA within the infected cell. Of the following, which is the most appropriate conclusion you could draw?

Accepted Answer

The genome being the complement of viral mRNA indicates it is a negative-sense RNA virus, which requires an RNA-dependent RNA polymerase to synthesize mRNA from its genome. Thus, the virion must contain a polymerase.

Question 6

The purified genome of certain viruses can enter a cell and elicit the production of progeny viruses (i.e., the genome is infectious). Regarding these viruses, which one of the following statements is most accurate?

Accepted Answer

Positive polarity RNA viruses can directly use their RNA as mRNA for protein synthesis, making the genome itself infectious.

Question 7

Regarding viral replication, which one of the following is most accurate?

Accepted Answer

Early proteins are typically enzymes involved in viral replication, while late proteins are structural proteins like capsid proteins.

Question 8

Each of the following statements concerning retroviruses is correct EXCEPT:

Accepted Answer

Retroviruses have a single-stranded RNA genome, not three segments of double-stranded RNA.

Question 9

Which one of the following choices names two viruses that both translate their messenger RNA into precursor polypeptides that must be cleaved by virion-encoded proteases?

Accepted Answer

Both human immunodeficiency virus (HIV) and poliovirus translate their mRNA into large precursor polypeptides that are subsequently cleaved by virion-encoded proteases to produce functional viral proteins.

Question 10

Which one of the following statements about virion structure and assembly is CORRECT?

Accepted Answer

Enveloped viruses often use a matrix protein to facilitate the interaction between the viral envelope glycoproteins and the structural proteins of the nucleocapsid, aiding in the assembly and stability of the virion.

Question 11

Each of the following statements concerning viruses is correct EXCEPT:

Accepted Answer

Viruses do not replicate by binary fission; they require a host cell to reproduce, using the host's machinery to replicate their genetic material and produce new viral particles.

Question 12

Viruses are obligate intracellular parasites. Each of the following statements concerning this fact is correct EXCEPT:

Accepted Answer

Viruses do not necessarily degrade host cell DNA to obtain nucleotides; they can use the host's cellular machinery to replicate their own genome without degrading the host DNA.

Question 13

The ability of a virus to produce disease can result from a variety of mechanisms. Which one of the following mechanisms is LEAST likely?

Accepted Answer

Viruses typically do not produce exotoxins; this is a mechanism more commonly associated with bacterial pathogens.

Question 14

Each of the following statements concerning viral surface proteins is correct EXCEPT:

Accepted Answer

Viral surface proteins do not participate in active transport of nutrients across the viral envelope membrane; their primary roles include mediating virus entry into host cells and eliciting immune responses.

Question 15

Many viruses mature by budding through the outer membrane of the host cell. Each of the following statements regarding these viruses is correct EXCEPT:

Accepted Answer

Viruses that mature by budding through the host cell membrane acquire an envelope from the host cell's lipid bilayer, so they all have an envelope.

Question 16

Viruses enter cells by adsorbing to specific sites on the outer membrane of cells. Each of the following statements regarding this event is correct EXCEPT:

Accepted Answer

The interaction between a virus and the cell membrane does not determine whether the purified genome of a virus is infectious. The infectivity of a purified viral genome is determined by its ability to replicate and produce viral particles once inside a host cell, not by the initial adsorption to the cell membrane.

Question 17

Each of the following statements concerning viral serotypes is correct EXCEPT:

Accepted Answer

Serotype is determined by the proteins on the virus surface, not by the RNA polymerase.

Question 18

The ability of a virus to produce disease can result from a variety of mechanisms. Which one of the following mechanisms is LEAST likely?

Accepted Answer

Viruses typically do not produce exotoxins; this is a mechanism more commonly associated with bacterial pathogens.

Question 19

All the following is correct as regard viral envelope except

Accepted Answer

The viral envelope is sensitive to alcohol, which can disrupt the lipid bilayer and inactivate the virus.

Question 20

All of the following is true about viruses except

Accepted Answer

Viruses contain either DNA or RNA as their genetic material, but not both.

Quiz 1: General Virology

The proteins on the external surface of viruses serve several important functions. Regarding these proteins, which one of the following statements is most accurate?

If a virus has an envelope, it is more easily inactivated by lipid solvents and detergents than viruses that do not have an envelope. Which one of the following viruses is the most sensitive to inactivation by lipid solvents and detergents?

All of the following is correct as regard viruses Except

Many viruses are highly specific regarding the type of cells they infect. Of the following, which one is the most important determinant of this specificity?

The purified genome of certain viruses can enter a cell and elicit the production of progeny viruses (i.e., the genome is infectious) . Regarding these viruses, which one of the following statements is most accurate?

Regarding viral replication, which one of the following is most accurate?

Each of the following statements concerning retroviruses is correct EXCEPT:

Which one of the following choices names two viruses that both translate their messenger RNA into precursor polypeptides that must be cleaved by virion-encoded proteases?

Which one of the following statements about virion structure and assembly is CORRECT?

Each of the following statements concerning viruses is correct EXCEPT:

Viruses are obligate intracellular parasites. Each of the following statements concerning this fact is correct EXCEPT:

The ability of a virus to produce disease can result from a variety of mechanisms. Which one of the following mechanisms is LEAST likely?

Each of the following statements concerning viral surface proteins is correct EXCEPT:

Many viruses mature by budding through the outer membrane of the host cell. Each of the following statements regarding these viruses is correct EXCEPT:

Viruses enter cells by adsorbing to specific sites on the outer membrane of cells. Each of the following statements regarding this event is correct EXCEPT:

Each of the following statements concerning viral serotypes is correct EXCEPT:

The ability of a virus to produce disease can result from a variety of mechanisms. Which one of the following mechanisms is LEAST likely?

All the following is correct as regard viral envelope except

All of the following is true about viruses except