Q: Which mechanism of action is typical for antiviral drugs targeting HIV?

Inhibition of reverse transcriptase enzyme ($$\text{RT})$$

Question 1

Which of the following best explains why viruses are not considered living organisms?

Accepted Answer

They lack a cell membrane and cannot reproduce independently.

Question 2

A viral capsid is primarily composed of which type of molecule, and what is its main function?

Accepted Answer

Proteins; to protect viral genetic material and aid in host attachment.

Question 3

Enveloped viruses have certain advantages and disadvantages compared to naked viruses. Which statement is correct?

Accepted Answer

Enveloped viruses are more susceptible to desiccation and disinfectants, but can evade the immune system more effectively.

Question 4

Which virus is an example of a single-stranded RNA virus, and which is an example of a double-stranded DNA virus?

Accepted Answer

Influenza virus (ssRNA); Adenovirus (dsDNA)

Question 5

Antigenic shift and antigenic drift are important concepts in viral evolution. Which statement correctly describes their significance?

Accepted Answer

Antigenic shift results in major changes in viral antigens, potentially causing pandemics, while antigenic drift involves minor changes leading to seasonal epidemics.

Question 6

A virus infects only liver cells in humans but not other cell types. This specificity is best described as:

Accepted Answer

Tropism

Question 7

Which of the following best distinguishes the lytic replication pathway from the lysogenic pathway in bacteriophages?

Accepted Answer

Lytic pathway results in immediate destruction of the host cell, while lysogenic pathway integrates viral DNA into the host genome.

Question 8

Which sequence correctly lists the major steps of a typical viral infection?

Accepted Answer

Attachment, penetration, uncoating, replication, assembly, release

Question 9

A patient experiences repeated outbreaks of herpes simplex virus, with periods of no symptoms. This infection is best classified as:

Accepted Answer

Latent persistent infection

Question 10

How can viral infections contribute to the development of cancer?

Accepted Answer

Some viruses integrate their DNA into host cells, disrupting normal cell cycle regulation and promoting oncogenesis.

Question 11

Which laboratory method is most commonly used to detect viral genetic material?

Accepted Answer

Polymerase Chain Reaction ($$PCR)$$

Question 12

Which mechanism of action is typical for antiviral drugs targeting HIV?

Accepted Answer

Inhibition of reverse transcriptase enzyme ($$	ext{RT})$$

Question 13

Which of the following is NOT a prion disease?

Accepted Answer

Rotavirus infection

Question 14

Which feature of the gastrointestinal tract most effectively limits digestive system infections?

Accepted Answer

Low pH of stomach acid ($$pH \approx 2)$$

Question 15

A patient presents with bloody diarrhea, abdominal pain, and fever. Which term best describes this clinical presentation?

Accepted Answer

Dysentery

Question 16

Which method is most appropriate for identifying causative agents in patients with intestinal symptoms?

Accepted Answer

Stool culture and molecular testing

Question 17

Which of the following is a major virulence factor for Vibrio cholerae, the causative agent of cholera?

Accepted Answer

Production of cholera toxin ($$	ext{CTX})$$

Question 18

Foodborne infection and food poisoning differ in their pathogenesis. Which statement is correct?

Accepted Answer

Foodborne infection involves ingestion of pathogens that multiply in the host, while food poisoning results from ingestion of preformed toxins.

Question 19

Why is the respiratory system the most common portal of entry for microbes?

Accepted Answer

It is constantly exposed to airborne particles and has a large surface area.

Question 20

Which disease is caused by Streptococcus pyogenes and can lead to complications such as rheumatic fever?

Accepted Answer

Pharyngitis

Comprehensive Study Guide: Viruses, Prions, Digestive and Respiratory System Infections

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