AP-Micro Virology: Structure, Replication, and Diagnosis 2

Question 1

The eclipse period in the viral replication cycle is defined as the time when:

Accepted Answer

Infectious virions cannot be detected inside or outside the infected cell

Answer

During the eclipse period the virus has uncoated and been disassembled, so no intact infectious particles are detectable until new assembly begins.

Question 2

In lysogenic viral infection, the integrated viral genome within the host chromosome is called a:

Accepted Answer

Prophage (provirus)

Answer

The integrated viral genome in a lysogenic cell is called a prophage (for bacteriophages) or provirus (for animal viruses), replicating silently with the host.

Question 3

During which step of viral replication are viral nucleic acids and proteins synthesized using host machinery?

Accepted Answer

Biosynthesis

Answer

Biosynthesis is the phase in which viral genomes are replicated and viral mRNAs are transcribed and translated into structural and nonstructural proteins.

Question 4

Cytopathic effects (CPE) observed in viral cell cultures include all of the following EXCEPT:

Accepted Answer

Increased host cell proliferation (hyperplasia)

Answer

CPE represents cytodestructive changes caused by viral infection; uncontrolled proliferation is not a feature of CPE, though some oncogenic viruses can transform cells.

Question 5

Enveloped viruses acquire their lipid membrane during release by:

Accepted Answer

Budding through the host cell membrane, incorporating host lipids and viral glycoproteins

Answer

During budding, enveloped viruses incorporate viral glycoproteins into a patch of host cell membrane and pinch off as enveloped virions without lysing the cell.

AP Practice Test

AP Practice Test

AP-Micro Virology: Structure, Replication, and Diagnosis 2