Exam 35: Viruses

Viruses use the host's machinery to make copies of themselves.However,some human viruses require a type of replication that humans do not normally do.For example,humans normally do not have the ability to convert RNA into DNA.How can these types of viruses infect humans,when human cells cannot perform a particular role that the virus requires?

Mimivirus contains some of the genes required for protein synthesis.This is cited as support for which hypothesis about the origins of viruses?

Will treating a viral infection with antibiotics affect the course of the infection?

The first class of drugs developed to treat AIDS such as AZT were known as reverse transcriptase inhibitors.What was the mechanism by which they worked to treat HIV infections?

You isolate a cell infected with an adenovirus.What must you see when you examine the cell?

You are a physician,and you suspect your patient has a viral infection that has never been seen in humans.The infection is localized in the cells along the lining of the small intestine.The cells in this area are regularly sloughed off and replaced with new cells;that is,these cells are constantly dividing.When you isolate this new virus and incubate it in culture,you discover that it does not replicate well in cultures that have slowly dividing cells,but it does much more damage in cultures that have actively dividing cells.What do these findings suggest about this new virus?

You have isolated a newly discovered virus and are attempting to characterize it.You begin with its genome.You first isolate the virion-producing mRNA from culture cells infected with the virus.When you compare these mRNA with the viral genome,you find that they are complementary.What does this tell you?

When people die from HIV infections,it is usually because _____.

If a viral host cell has a mutation that interferes with the addition of carbohydrates to proteins in the Golgi,which of the following could likely result?

Which of the following supports the argument that viruses are nonliving?

It is believed that HIV has passed from chimps to humans more than once.This is very telling since it suggests that animal-to-human viral transmissions may be more common than previously thought.What is the best evidence in support of the conclusion that HIV made the chimp-to-human leap more than once?

HIV is inactivated in the laboratory after a few minutes of sitting at room temperature;the flu virus is still active after sitting for several hours.What are the practical consequences of these findings?

Viruses _____.

You just discovered a new virus.This virus infects heart muscle,where it causes inflammation.This virus has a very high mutation rate.Which of the following is the best strategy for finding a treatment for this virus?

What would the result be if a drug that blocks the action of polymerase was introduced into a virus-infected organism?

A biologist develops a new drug that seems to dramatically slow the onset of symptoms resulting from HIV infection.Close monitoring of HIV-infected cells reveals that the viral proteins are in the form of long polyproteins.What kind of drug did the biologist develop?

Which of the following viruses would be the most likely to have reverse transcriptase?

Which of the following human diseases is caused by a virus that requires reverse transcriptase to transcribe its genome inside the host cell?

A virus that has a single strand of RNA which it transcribes into complementary DNA is a _____.

The virus genome and viral proteins are assembled into virions during _____.