During the replication cycle of a DNA virus
A. reassortment is a common phenomenon
B. DNA replication precedes mRNA transcription
C. integration of the viral DNA genome into the host chromosome is an integral step of DNA replication
D. viral transcription is often divided between early and late gene classes
查看答案
Which one of the following statements regarding the replication of RNA viruses is true?
A. Polymerase-induced mutations occur at a lower frequency compared to DNA viruses
B. Replication of the RNA genome can be prevented by the nucleoside analog bromodeoxyuridine (BudR)
C. Some RNA polymerases are brought into the infected cell by the virus particle
D. Viral envelopes are not acquired from the cellular membrane
The defective viruses are due to defect of
A. spikes
B. capsid
C. genome
D. viral enzyme
Reverse transcriptase is an enzyme unique to the retroviruses.Which one of the following is a function of the reverse transcriptase?
A. DNase activity
B. RNA-dependent RNA polymerase activity
C. Integration activity
D. RNA-dependent DNA polymerase activity
Viruses enter cells by adsorbing to specific sites on the outer membrane of cells. Each of the following statements regarding this event is correct EXCEPT
A. The interaction determines the specific target organs for infection
B. The interaction determines whether the purified genome of a virus is infectious
C. The interaction can be prevented by neutralizing antibody
D. If the sites are occupied, interference with viral infection occurs