Question 1

Which of the following best describes the initial step in viral replication for most viruses?

Accepted Answer

Attachment of the virion to a specific receptor on the host cell surface

Question 2

During the penetration step of viral replication in bacteriophages, what typically happens?

Accepted Answer

Only the viral nucleic acid is injected into the host cell, leaving the protein coat outside

Question 3

Which equation best represents the exponential increase in the number of virions during the maturation phase of viral replication?

Accepted Answer

$N_t = N_0 e^{r t}$

Question 4

What is the role of host cell machinery during the synthesis step of viral replication?

Accepted Answer

It replicates the viral genome and synthesizes viral proteins

Question 5

Which of the following is a key difference between animal and plant virus entry into host cells?

Accepted Answer

Plant viruses require vectors such as insects or fungi for entry due to rigid cell walls

Question 6

Which statement best describes the latent phase of a viral infection?

Accepted Answer

The virus is dormant, sometimes integrated into the host genome, and symptoms appear only when the virus reactivates

Question 7

Which of the following viruses is known for causing oncogenic transformation in host cells?

Accepted Answer

Human Papillomavirus (HPV)

Question 8

What is the function of the E6 and E7 proteins encoded by Human Papillomavirus (HPV)?

Accepted Answer

They degrade tumor suppressor proteins, leading to uncontrolled cell proliferation

Question 9

Which of the following best describes the lytic cycle of bacteriophage replication?

Accepted Answer

Host cell is lysed, releasing new virions

Question 10

Which step in the viral replication cycle is responsible for the assembly of new virions?

Accepted Answer

Packaging of viral genome into capsid proteins

Question 11

A retrovirus contains which of the following enzymes that is essential for its replication?

Accepted Answer

Reverse transcriptase

Question 12

Which of the following is a plausible consequence of misexpression of a viral oncogene in a host cell?

Accepted Answer

Uncontrolled cell proliferation and possible tumor formation

Question 13

Which of the following best explains why plant viruses often require vectors for transmission?

Accepted Answer

Plant cell walls prevent direct viral entry, so viruses enter through wounds or are delivered by vectors

Question 14

Which of the following is NOT a possible effect of animal virus infection on host cells?

Accepted Answer

Immediate activation of host immune response

Question 15

Which of the following best describes the role of proto-oncogenes in normal cells?

Accepted Answer

They encode proteins that are key components of signaling pathways stimulating cell proliferation

Question 16

Which of the following is a correct sequence of events in the replication of a typical bacteriophage?

Accepted Answer

Attachment, penetration, synthesis, assembly, release

Question 17

Which of the following viruses is most likely to cause persistent infection in host cells?

Accepted Answer

Herpes simplex virus

Question 18

Which of the following is a plausible reason why bacteriophage T4 is considered virulent?

Accepted Answer

It kills the host cell by lysis after replication

Question 19

Which of the following is a distinguishing feature of retrovirus replication?

Accepted Answer

Reverse transcription of viral RNA into DNA and integration into the host genome

Question 20

Which of the following best describes the eclipse period in the one-step growth curve of viral replication?

Accepted Answer

The period when no infectious virions are detected in the host cell, as viral components are being synthesized

Viral Replication and Diversity: Microbiology Study Notes

Study Guide - Practice Questions