Viral Replication/Transcription/Translation Examples Flashcards
In which stage is the viral DNA introduced into the cell? (Virulent Bacteriophages)
Penetration
In which stage does formation of mature viruses occur? (Virulent Bacteriophages)
Assembly
The host DNA is usually degraded during which stage? (Virulent Bacteriophages)
Biosynthesis
What would be the fate of a lytic bacteriophage if the host cell died prior to the assembly stage?
(Virulent Bacteriophages)
The virus would not be able to infect new hosts.
Lysogenic viral DNA integrating into the host genome is referred to as
(Temperate Bacteriophages)
a prophage.
Which of the following events might trigger induction of a temperate bacteriophage?
(Temperate Bacteriophages)
Exposure to UV light
How is the lytic cycle different from the lysogenic cycle with respect to the infected host cell?
(Temperate Bacteriophages)
The host cell dies during the lytic stage.
What is the fate of the prophage during the lysogenic stage?
(Temperate Bacteriophages)
It is copied every time the host DNA replicates.
Are virophages a type of virus or something different?
It must have a capsid and a nucleic acid, which can be double-stranded or single-stranded, circular or linear, and DNA or RNA. Virophages are therefore a type of virus.
Virophages only
- smaller than bacteria and archaea
- lack genes for proteins needed to self replicate
Non-virophage viruses only
genetic information can be in the form of DNA and RNA
Both virophages and other viruses
-can’t replicate on their own
- don’t belong to the 3 domains
- have a protein capsid surrounding their nucleic acid
Neither virophages nor other viruses
- generate energy through mitochondria
- use ribosomes to make proteins
what is another way that cells have evolved to avoid viral infection?
An attachment receptor on the host cell surface that is recognized by the virus is mutated.
Viruses have many types of life cycles and can go through phases during which they are actively replicating and destructive to the host cell or dormant within the host cell. These life cycles differ in different types of viruses, so the cycle of megaviruses differs from those of bacteria and animals. During which part of the bacteriophage life cycle will the viral genome be replicated in synchrony with the host cell?
lysogenic
When packaged in the virion, the complete complex of nucleic acid and protein is known as the virus
nucleocapsid
Reverse transcriptase is a(n)
RNA-dependent DNA polymerase.
The latent phase in the viral growth curve and the lag phase of the bacterial growth curve are equivalent and represent the time it takes for the virus or bacterium to adapt to the culture conditions and begin growing.
False
Viral proteins are categorized as early, middle, and late. Early proteins typically are necessary for
production of viral mRNA and copying the viral genome.
T4 genes are transcribed by host RNA polymerase, yet this transcription is carefully controlled so that groups of T4 genes are transcribed in a specific order after infection. How is this accomplished?
Early and middle T4 genes encode for RNA polymerase-modifying proteins so that only phage promoters are recognized.
