Question 1

Which of the following best describes why viruses are considered obligate intracellular parasites?

Accepted Answer

They require living host cells to multiply.

Question 2

A scientist is attempting to culture a newly discovered virus. Which of the following methods would NOT be suitable for viral cultivation?

Accepted Answer

Inoculation into a nutrient agar plate without living cells

Question 3

Which of the following statements about viral structure is correct?

Accepted Answer

The capsid is made of protein subunits called capsomeres.

Question 4

A virus with a helical capsid and an envelope is most likely to:

Accepted Answer

Be sensitive to heat and possess glycoprotein spikes.

Question 5

Which of the following best explains the host range of a virus?

Accepted Answer

The presence of specific attachment sites and cellular factors in the host

Question 6

Which of the following is a key difference between the lytic and lysogenic cycles of bacteriophages?

Accepted Answer

The lytic cycle results in immediate lysis of the host cell, while the lysogenic cycle involves integration of phage DNA as a prophage.

Question 7

A patient is diagnosed with a persistent viral infection. Which of the following best describes this type of infection?

Accepted Answer

The infection develops gradually over a long period and is generally fatal.

Question 8

Which of the following laboratory techniques is used to identify viruses based on their reaction with specific antibodies?

Accepted Answer

Western blotting

Question 9

Which of the following best describes the replication of a + (sense) strand RNA virus?

Accepted Answer

The viral RNA serves directly as mRNA for protein synthesis.

Question 10

Which of the following is a characteristic of prions?

Accepted Answer

They are proteinaceous infectious particles that cause spongiform encephalopathies.

Question 11

A virus is classified in the family Herpesviridae. What is the correct format for its genus name?

Accepted Answer

Simplexvirus

Question 12

Which of the following best explains why antibiotics are ineffective against viruses?

Accepted Answer

Viruses lack peptidoglycan cell walls targeted by antibiotics.

Question 13

Which of the following is a real-world example of a latent viral infection?

Accepted Answer

Cold sores caused by herpes simplex virus

Question 14

Which of the following viruses is associated with the development of cancer due to integration of viral DNA into the host genome?

Accepted Answer

Human papillomavirus (HPV)

Question 15

Which of the following steps is unique to the multiplication of animal viruses compared to bacteriophages?

Accepted Answer

Uncoating of the viral nucleic acid by host or viral enzymes

Question 16

A patient is infected with a retrovirus. Which enzyme is essential for the replication of this virus?

Accepted Answer

Reverse transcriptase

Question 17

Which of the following best describes the process of specialized transduction?

Accepted Answer

A phage transfers only specific pieces of bacterial DNA to another bacterium during the lysogenic cycle.

Question 18

Which of the following is true regarding viroids?

Accepted Answer

They are composed solely of a short strand of circular, single-stranded RNA.

Question 19

Which of the following best explains how prions cause disease?

Accepted Answer

They convert normal cellular prion proteins (PrPC) into the infectious form (PrPSc), leading to accumulation and cell death.

Question 20

A laboratory technician observes clear zones, or plaques, on a bacterial lawn after incubation with a bacteriophage. What does each plaque represent?

Accepted Answer

A single virus that has lysed a host cell and its progeny

Chapter 13 microbio

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