Question 1

Which of the following best describes the structure of an enveloped virus, as shown in the provided images?

Accepted Answer

A nucleic acid genome surrounded by a protein capsid, with an additional lipid bilayer containing glycoproteins derived from the host cell.

Question 2

A virus with a helical capsid symmetry will have its length determined by which of the following factors?

Accepted Answer

The length of its nucleic acid.

Question 3

Which of the following is a correct stepwise order for the lytic replication cycle of a bacteriophage, as depicted in the diagrams?

Accepted Answer

Attachment → Penetration → Synthesis → Assembly → Release

Question 4

In a plaque assay, what does each clear zone (plaque) on a bacterial lawn represent?

Accepted Answer

Infection and lysis of host cells by a single virus particle.

Question 5

Which enzyme is critical for the release of bacteriophage T4 from its host cell, and what is its function?

Accepted Answer

Lysozyme; it degrades the peptidoglycan layer of the bacterial cell wall.

Question 6

Which of the following best explains the concept of 'circular permutation' in the context of bacteriophage T4 DNA packaging?

Accepted Answer

The same set of genes is present in each genome, but the order varies due to different starting points during packaging.

Question 7

A virus with a single-stranded RNA genome that serves directly as mRNA is classified as which type of virus?

Accepted Answer

Positive-strand RNA virus

Question 8

Which of the following is a unique feature of retroviruses compared to typical RNA viruses?

Accepted Answer

They use reverse transcriptase to synthesize DNA from their RNA genome.

Question 9

Which of the following best describes the latent period in a one-step viral growth curve?

Accepted Answer

The time during which no infectious virions are detected in the medium, encompassing both eclipse and maturation phases.

Question 10

Which of the following is a possible consequence of viral infection in animal cells, as shown in the provided diagrams?

Accepted Answer

Transformation of the cell into a tumor cell.

Question 11

Which of the following statements about the Baltimore classification system is correct?

Accepted Answer

It classifies viruses based on their genome type and replication strategy.

Question 12

Which of the following best describes the function of the viral enzyme neuraminidase?

Accepted Answer

It cleaves glycosidic bonds to allow liberation of viruses from host cells.

Question 13

A bacteriophage that can integrate its genome into the host chromosome and remain dormant is called:

Accepted Answer

A temperate phage

Question 14

Which of the following is a correct description of a nucleocapsid?

Accepted Answer

The complete complex of nucleic acid and protein packaged in the virion.

Question 15

Which of the following best explains why some RNA viruses must carry their own RNA-dependent RNA polymerase within the virion?

Accepted Answer

Their genome cannot be directly translated by host ribosomes and must first be transcribed into mRNA.

Question 16

Which of the following is a correct real-world application of the plaque assay technique?

Accepted Answer

Determining the titer of infectious virus particles in a sample.

Question 17

Which of the following best describes the process of terminal redundancy in viral genomes?

Accepted Answer

Some DNA sequences are duplicated on both ends of the genome.

Question 18

Which of the following is a key difference between a naked virus and an enveloped virus, as shown in the diagrams?

Accepted Answer

An enveloped virus has a lipid bilayer derived from the host cell, while a naked virus does not.

Question 19

Which of the following best describes the function of the capsid in a virus?

Accepted Answer

It protects the viral genome and aids in the delivery of the genome into host cells.

Viruses and Eukaryotes: Structure, Classification, and Replication

Study Guide - Practice Questions