| Degrading the viral envelope 4. Once a prophage is formed, the viral genes are reproducedevery time the bacterium multiplies. The genes that encode thelytic cycle are held in check by a repressor protein. Stressinduces the formation of proteases that degrade the repressor. Howwould this affect the prophage? | Apoptosis would be induced. | | The virus enters the lyticcycle. | | The bacterial genome isdenatured. | | The bacterium rejects the viral genes. 5. Can a virus be killed? | No, viruses are non-living andcannot die. | | No, viruses are capable ofself-assembly and cannot be permanently killed. | | Yes, separating the genes from thecapsid kills it. | | Yes, destroying its genome kills it. 6. Which class of drugs would be effective against HIV but notagainst most other pathogenic viruses? | Translation inhibitors that stopassembly of viral proteins. | | Nucleotide analogs that haltreplication. | | Non-nucleoside reversetranscriptase inhibitors that block reverse transcription. | | Receptor antagonists that block viral entry. 7. An unscrupulous malcontent writes a computer program andembeds it in an e-mail that promises lucrative investmentopportunities. The e-mail is sent to thousands of anonymous users,when they open it the program copies itself into the computer'shard drive. The hard drive begins to fill up with copies of theprogram, once it is completely full the computer crashes. Match thecomponents of this story with the components of a viral lifecycle. 1. e-mail containing virus | Virus | | 2. Innocent user | Binding site onhostcell | | 3. User's hard drive andCPU | Host cell'sribosomes | | 4. Program | Uninfected host cell | | | | | 8. Vaccines work by priming the immune system and inducing theformation of antibodies and memory cells. When the actual virusinfects the host the host's immune system recognizes it andresponds to it. Which feature of viruses helps them thwart thissystem? | The envelops prevents immune systemrecognition. | | Autocatalytic proteins replicatewithout genetic material. | | The high mutation rate of the viralgenome. | | Integration of viral genescamouflages the virus. | | Shedding the capsid inactivates theantibodies. | |