ap bio 17

Which of the following series of events best reflects what we know about how the flu virus moves between species?

An animal such as a pig is infected with more than one virus, genetic recombination occurs, the new virus mutates and is passed to a new species such as a bird, and the virus mutates and can be transmitted to humans.

What is the function of reverse transcriptase in retroviruses

It uses viral RNA as a template for DNA synthesis

If you already knew that the infectious agent was either bacterial or viral, which treatment would allow you to distinguish between these two possibilities?

III

Which of the following statements correctly describes the most probable fate of a newly emerging virus that causes high mortality in its host?

The newly emerging virus will die out rather quickly or will mutate to be far less lethal.

Which of the following statements correctly describes one difference between vertical and horizontal transmission of plant viruses?

Vertical transmission is transmission of a virus from a parent plant to its progeny, and horizontal transmission is one plant spreading the virus to another plant.

Which of the following statements accurately describes plant virus infections?

They are spread via the plasmodesmata.

Why are retroviruses considered a special class of viruses?

They transcribe RNA to DNA using reverse transcriptase.

which of the following statements correctly describes one characteristic of the lytic cycle of viral replication

a large number of phages are released at a time

Which of the following is why someone who has had a Hesperus-mediated cold sore or genital sore may have flare-ups for the rest of his or her life

copies of the herpes virus genome remaining as mini-chromosomes in some host cell nuclei

Which of the three types of viruses shown in the figure would you expect to include a capsid(s) as part of their overall structure?

all three

Viral envelopes can best be analyzed with which of the following techniques?

antibodies against specific proteins not found in the host membranes

In order to be able to remain latent in an infected live cell, HSV must be able to shut down what process?

apoptosis of a virally infected cell

RNA viruses require their own supply of certain enzymes because __________.

host cells lack enzymes that can replicate the viral genome

Which of the following characteristics, structures, or processes is common to both bacteria and viruses?

genetic material composed of a nucleic acid

Which of the following processes can be effective in preventing the onset of viral infection in humans?

getting vaccinated

In the figure, at the arrow marked II, what enzyme(s) are being utilized?

host cell DNA polymerase

Antiviral drugs that have become useful are usually associated with which of the following properties?

interference with viral replication

Which viruses have single-stranded RNA that acts as a template for DNA synthesis?

retroviruses

Which of the following characteristics determine a virus's host range?

the proteins on its surface and that of the host

Based on the table, which virus meets the Baltimore requirements for a retrovirus?

D

Based on the table, which virus meets the requirements for a bactiophage

A

Emerging viruses arise by __________.

All of the listed responses are correct

Why are viruses called obligate intracellular parasites?

All of the listed responses are correct.

Why is it ineffective to treat viral disease with antibiotics?

Antibiotics inhibit enzymes specific to bacteria and have no effect on virally encoded enzymes.

Which of the three types of viruses shown in the figure would you expect to include glycoproteins as part of their overall structure?

I and II only

What happens first when a phage infects a bacterial cell and is going to enter a lysogenic cycle?

Linear DNA circularizes.

Why do RNA viruses tend to have unusually high rates of mutation?

Replication of their genomes does not involve proofreading

A bacterium is infected with an experimentally constructed bacteriophage composed of the T2 phage protein coat and T4 phage DNA. The new phages produced would have __________.

T4 protein and T4 DNA

In electron micrographs of HSV infection, it can be seen that the intact virus initially reacts with cell-surface proteoglycans, then with specific receptors. This is later followed by viral capsids docking with nuclear pores. Afterward, the capsids go from being full to being "empty." Which of the following statements best describes these observations?

The viral envelope mediates entry into the cell, the capsid enters into the nuclear membrane, and the genome is all that enters the nucleus.

Which of the following statements correctly describes the best predictor of how much damage a virus causes?

ability of the infected cell to undergo normal cell division

A human pandemic is

an epidemic that extends around the world

The nucleic acid of a virus particle is enclosed in a protein coat. What is it called?

capsid

If you already knew that the infectious agent was a prion, which treatment would allow you to distinguish this?

either I or IV

If scientists are trying to use what they know about HSV to devise a means of protecting other people from being infected, which of the following would have the best chance of lowering the number of new cases of infection?

interference with new viral replication in preexisting cases

In the figure, when new viruses are being assembled (IV), what mediates the assembly?

nothing; the proteins self- assemble

What is a virus that attacks a bacterium?

phage

HIV uses which of the following processes to synthesize a DNA strand using its RNA genome as a template?

reverse transcription

which of the following statements correctly describes the lysogenic cycle of lambda phage

the phage genome replicates along with the host genome

A researcher lyses a cell that contains nucleic acid molecules and capsomeres of tobacco mosaic virus (TMV). The cell contents are left in a covered test tube overnight. The next day this mixture is sprayed on tobacco plants. Which of the following would be expected to occur?

the plants would develop the typical symptoms of TMV infection

Which of the following responses correctly lists the order of events in a generalized viral replicative cycle?

the virus enters the cell, host enzymes replicate the viral genome, enzymes transcribe the viral genome into mRNA

most molecular biologist think that viruses originated from naked bits of cellular nucleic acid. which of the following support this theory

viral genomes are usually similar to the genome of the host cell.