Viruses Flashcards
viruses are unable to reproduce without a –
host cell
because viruses lack typical cell structures such as organelles they are much – than any prokaryotic or eukaryotic cell
smaller
virus need – and a protective protein coat (capsid)
genetic material (RNA or DNA)
viruses are able to – in that if a viral genome and capsize proteins are mixed together, viral particles will form
self-assemble
T/F: viral genome can consists of only a few genes or can range up to a few hundred genes
true
viruses are – to the type of host cell that they can infect
specific
in order for a virus to infect a cell, that cell must have a – for the virus
receptor
while it seems odd that cells would evolve receptors for viruses, it is usually a case of –
mistaken identity
viruses can actually – another substance for which the cell has a legitimate need and thus has a receptor for
mimic
after binding to a receptor on the membrane of the host cell, viral genetic material enters the host by either injecting itself across the cell membrane or by being taken in by –
endocytosis
– are the primary way to induce variation into the viral pop
mutations
animal viruses are usually categorized according to the type of – they possess as well as whether it is single or double stranded
nucleic acid
once the DNA or RNA of the animal virus is taken in by the host cell, the virus may immediately become – using the host cell machinery to transcribe and translate the viral genes
active
the release of new animal viruses can be via – of the cell membrane which immediately kills the host cell
lysis
the release of new animal viruses can be via – where the new viruses are shipped out of the host cell via exocytosis
budding
T/F: budding does not immediately kill the host cell but may eventually prove fatal to the host
true
viruses may become – integrating itself into the chromosomes of the host cell, where it may stay for varying amounts of time
latent
eventually the latent virus will – from the host chromosome and it will become active to produce and release new viruses
excise
T/F: some viruses are capable of alternating between active and latent forms multiple times
true
infections caused by specific – viruses such as cold sores and genital – are notorious for alternating between active and latent forms
herpes
first retrovirus discovered
human immunodeficiency virus (HIV)
enter the cell in RNA form that must be converted to DNA form
retroviruses
process of converting viral RNA backward into DNA
reverse transcription
reverse transcription is achieved by an enzyme called – which is present inside the virus when it enters the host cell
reverse transcriptase
reverse transcriptase will produce a DNA copy of the RNA, thereby forming a –
DNA/RNA hybrid
the same reverse transcriptase will then convert the DNA/RNA hybrid into – that will be converted into mRNA by the virus by using the host’s polymerase
double-stranded DNA
In the case of HIV, the DNA integrates into the chromosomes of a host cell (which is a specific cell type in the immune system) and enters a latent phase that may last more than – years
10
When the HIV’s DNA excises from the host chromosome it becomes active and begins producing new viruses. When this happens on a mass scale, the death host cells will signal the beginning of deterioration in the immune system, which causes –
acquired immunodeficiency syndrome (AIDS)
