Question 1

Which of the following statements best explains why viruses are considered obligatory intracellular parasites?

Accepted Answer

They require living host cells to multiply because they lack ribosomes and an ATP-generating mechanism.

Question 2

A scientist observes a virus with a helical capsid structure under an electron microscope. Which virus is most likely being observed?

Accepted Answer

Rabies virus

Question 3

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

Accepted Answer

Transfer of specific bacterial genes by a lysogenic phage during excision from the host chromosome

Question 4

A patient is diagnosed with a persistent viral infection. Which of the following graphs best represents the number of virions over time in this type of infection?

Accepted Answer

A gradual increase in virions over months or years

Question 5

Which of the following is a unique feature of retroviruses such as HIV?

Accepted Answer

They use reverse transcriptase to synthesize DNA from an RNA template.

Question 6

Which of the following is NOT a component of all viruses?

Accepted Answer

Envelope

Question 7

A bacteriophage infects E. coli and integrates its DNA into the host genome without causing immediate lysis. What is the integrated phage DNA called?

Accepted Answer

Prophage

Question 8

Which of the following best explains why some viruses are host-specific?

Accepted Answer

They can only infect cells with compatible receptor sites and cellular factors.

Question 9

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

Accepted Answer

Uncoating of the viral capsid by host or viral enzymes

Question 10

A laboratory is using a plaque assay to quantify bacteriophages. What does each plaque on the bacterial lawn represent?

Accepted Answer

A single virus particle that initiated infection

Question 11

Which of the following is a consequence of lysogeny in bacteria?

Accepted Answer

The host cell becomes immune to reinfection by the same phage.

Question 12

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 13

Which of the following best describes the function of viral spikes?

Accepted Answer

They facilitate attachment to host cell receptors.

Question 14

A patient presents with symptoms of Creutzfeldt-Jakob disease. Which infectious agent is responsible for this disease?

Accepted Answer

A prion

Question 15

Which of the following best explains why prion diseases are difficult to treat?

Accepted Answer

Prions are resistant to standard sterilization procedures because they lack nucleic acids.

Question 16

Which of the following is a correct sequence of events in the lytic cycle of a T-even bacteriophage?

Accepted Answer

Attachment → Penetration → Biosynthesis → Maturation → Release

Question 17

Which of the following best describes the Baltimore classification system for viruses?

Accepted Answer

It is based on the type of nucleic acid and how mRNA is produced.

Question 18

Which of the following laboratory methods is commonly used to grow viruses for vaccine production?

Accepted Answer

Inoculation into embryonated eggs

Question 19

Which of the following is a key difference between the multiplication of DNA viruses and RNA viruses in animal cells?

Accepted Answer

DNA viruses replicate in the nucleus using host enzymes, while RNA viruses often replicate in the cytoplasm.

Question 20

Which of the following best describes the process of viral budding?

Accepted Answer

The virus acquires its envelope from the host cell plasma membrane during release.

Chapter 13

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Study Guide - Flashcards