Question 1

Which of the following best describes the process shown in the second image, where two different viral strains coinfect a single host cell and produce a virus with a new genetic combination?

Accepted Answer

Antigenic shift

Question 2

A patient is diagnosed with a viral infection that shows periods of high viral replication followed by periods of dormancy, as seen in the first image. Which type of infection does this represent?

Accepted Answer

Latent persistent infection

Question 3

Which of the following statements about the release of animal viruses, as depicted in the third image, is correct?

Accepted Answer

Enveloped viruses acquire their envelope by budding from the host cell membrane.

Question 4

In the fourth image, which laboratory technique is being used to detect the presence of viral antigens or patient antibodies?

Accepted Answer

Agglutination test

Question 5

Based on the fifth image, which of the following is a correct pairing of viral genome type and an example virus?

Accepted Answer

dsDNA, nonenveloped: Adenovirus

Question 6

A microbiologist streaks a clinical sample on mannitol salt agar and observes yellow colonies, as shown in the sixth image. What does this indicate about the organism?

Accepted Answer

It is a Staphylococcus species that ferments mannitol.

Question 7

Refer to the seventh image. During which step of the lytic replication cycle does the bacteriophage inject its genetic material into the host cell?

Accepted Answer

Penetration

Question 8

A laboratory is using a chemostat, as shown in the eighth image, to culture bacteria. What is the main advantage of this system?

Accepted Answer

It maintains bacterial growth at a constant rate by continuously adding fresh medium and removing waste.

Question 9

Which of the following best explains why enveloped viruses are generally more sensitive to detergents and drying than naked viruses?

Accepted Answer

Their lipid envelope is easily disrupted, which is essential for infectivity.

Question 10

A patient sample is tested for a viral infection using an agglutination test, as shown in the fourth image. Which of the following is a limitation of this test?

Accepted Answer

It may give false negatives if antigen levels are low.

Question 11

Which of the following best describes the process of antigenic drift in influenza viruses?

Accepted Answer

A gradual accumulation of minor genetic mutations in viral genes encoding surface proteins.

Question 12

Which of the following is a key feature of a latent persistent infection, as shown in the first image?

Accepted Answer

Intermittent flare-ups with periods of dormancy and low or undetectable viral replication.

Question 13

Which of the following best explains why RNA viruses tend to evolve faster than DNA viruses?

Accepted Answer

RNA-dependent RNA polymerases lack proofreading ability, leading to higher mutation rates.

Question 14

A virus is classified as a retrovirus. Which of the following steps is unique to its replication cycle?

Accepted Answer

Reverse transcription of viral RNA to DNA by reverse transcriptase.

Question 15

Which of the following best describes the function of hemagglutinin (HA) spikes on the influenza virus surface?

Accepted Answer

They help the virus attach to and enter host cells by binding to sialic acid.

Question 16

Which of the following is a correct statement about the use of mannitol salt agar (MSA) and eosin methylene blue (EMB) agar, as shown in the sixth image?

Accepted Answer

EMB is selective for Gram-negative bacteria and differentiates lactose fermenters.

Question 17

Which of the following best describes the role of lysozyme in the lytic replication cycle of bacteriophages, as shown in the seventh image?

Accepted Answer

It breaks down the host cell wall to allow release of new phages.

Question 18

A virus is found to have a segmented RNA genome. Which of the following is a potential consequence of this genome arrangement?

Accepted Answer

It can undergo reassortment if two different strains infect the same cell.

Question 19

Which of the following best explains why prion diseases are difficult to eliminate from surgical equipment?

Accepted Answer

Prions are highly resistant to heat, chemicals, and radiation, requiring more aggressive sterilization methods.

Viruses, Prions, and Fundamentals of Microbial Growth: Structured Study Notes

Guida di studio - Domande di pratica

Study guide - Flashcard