Viruses Flashcards
what are viruses?
intra cellular parasites
what are their living characteristics?
they replicate
they have a genome
they have protein
they are alive
when are viruses alive and when do they replicate?
only in a living host
what are their nonliving characteristics?
no metabolism
no growth
no regular cell components/ organelles
are viruses cells?
no
what is a virus’ 2 main components
genome and protein coat
what is a genome?
RNA or DNA (aka nucleic acid)
what is a protein coat?
capsid
which kingdom do viruses fit into?
none
how can viruses be classified?
- what organisms they infect
- what genome they have
- what general shape they have
what types of viruses are there?
DNA
RNA (subgroup- retroviruses)
how large are viruses and how can they be seen?
20-400 nanometers; can only be seen in clusters under electroscopes
DNA or RNA virus
genome is double stranded
DNA
DNA or RNA virus
mutations are minimal
DNA
DNA or RNA virus
it maintains its identity- your immune system will always recognize it
DNA
DNA or RNA virus
can carry out the lysogenic cycle
DNA
what happens to the virus in the lysogenic cycle?
the virus remains dormant in the nucleus of the host cell
DNA or RNA virus
genome is single stranded
RNA
DNA or RNA virus
mutation can be a permanent change- your immune system might not recognize the new mutated virus
RNA
DNA or RNA virus
new antibodies need to be made
RNA
DNA or RNA virus
cannot carry out lysogenic cycle (does not have DNA)
RNA
retroviruses
what does reverse transcriptase (enzyme) allow them to do?
convert their RNA to DNA
retroviruses
as a result of reverse transcriptase, what can the virus now do?
carry out the lysogenic cycle
retroviruses
because they can mutate and lay dormant within host cells, are they more or less dangerous than DNA and non-retro RNA viruses?
more dangerous
what do viruses cause?
disease
how do viruses cause symptoms of disease?
destroying host cells
what are vaccines used for?
preventing viral infections
