Exam 17: Genetics of Viruses

If you created a strain of bacteria that overexpressed protease inhibitors, and then infected this bacteria with phage $\lambda$ , would you expect the phage to follow the lytic or lysogenic cycle?

The virus that causes chickenpox can also cause ______ decades later when it switches from the latent state and starts making new viral particles.

The ________ is an enveloped virus with spikes.

Because tobacco mosaic virus has an RNA genome, it must encode a reverse transcriptase.

Reverse transcriptase copies

When phage $\lambda$ enters the lytic cycle

What piece of the RNA HIV genome is used as a primer during the synthesis of double-stranded DNA from HIV RNA?

The reverse transcription of HIV RNA utilizes host cell tRNA as a primer. Specifically, a tRNA for lysine is utilized. Would a drug that blocked the host cell synthesis of the tRNA for lysine be a good drug to prevent the HIV life cycle?

A _______ uses the lytic cycle to begin the immediate manufacture of new phages in the host cells.

Latency in HIV occurs when

Most biologists consider viruses to be living organisms, which are classified with bacteria.

Gierer and Schramm isolated ______ from tobacco mosaic virus and applied it to plant tissue, which caused the same types of lesions that occurred when plants were exposed to intact tobacco mosaic virus.

The Gag polyprotein is cleaved into

You are working in a lab that studies tobacco mosaic virus (TMV). You wish to perform follow up experiments to the Fraenkel-Conrat/Singer experiments. You use the Holmes ribgrass (HR) strain of TMV that they used, which produces streaks along the veins and contains histidine and methionine in the TMV capsid protein. You also use a second TMV strain that you've isolated, called Purp, that causes purple lesions on the leaves, and lacks histidine and methionine in the TMV capsid protein. If you use Purp RNA and HR proteins to create reconstituted viruses, what lesions do you expect will form, and what will the amino acid composition of the capsid protein be?

Azidothymidine (AZT) is mentioned in your book as an HIV drug. AZT is a reverse transcriptase inhibitor. That means AZT is only effective during the ______ stage of the viral life cycle.

The HIV genome contains nine genes, and therefore encodes just nine proteins.

A _______ frequently integrates into the host genome, forming prophages and utilizing a lysogenic cycle to manufacture new phages.

Many scientists and drug companies have worked hard to produce drugs to stop various stages of the HIV life cycle. Some drugs have been tested that inhibit the function of Vpu. What stage of the HIV life cycle would such a drug inhibit?

Tetherin is a protein encoded in the human genome. Based on what you know about the interaction between Vpu and tetherin, what do you predict the broad cellular function of tetherin is?

What structure on bacteriophage $\lambda$ plays an analogous role to the spike glycoproteins in HIV?