Chapter 5 - viruses Flashcards
Viruses are _____________ ________ _________ (meaning they cannot function outside of a host cell).
intracellular obligate parasites
Viruses are typically between __ and ___ nanometers.
10 and 100
Virus genomes are typically between a few thousand to ______ nucleotides in length.
200,000
Viruses may contain ______ OR _______-stranded DNA or RNA.
single or double
The protein shell around a genome is called a ______.
capsid
Capsids are composed of many __________ proteins.
capsomere
When a capsid and genome are together, the structure is called a ____________.
nucleocapsid
Viruses could possibly have an ________ (plasma membrane taken from a host cell around the capsid).
envelope
Capsids often exhibit either _______ or ___________ (sometimes called polyhedral) shapes.
helical, icosahedral
If a plasma membrane surrounds the nucleocapsid, the virus is “_________.”
enveloped
If there is no plasma membrane, the virus is “_____.”
naked
Enveloped viruses are mostly associated with _______ (including ______) as their hosts.
animals, humans
A virus must:
- stick to a host cell (______)
- get into the cell (_________) and release its genome (______)
- express its genes to make proteins (_________)
- replicate its genome (_________)
- put everything together (________) and get the new virus particles out (____)
adhere, penetrate, uncoat, synthesis, synthesis, assembly, exit
In the replication cycle, _____ is arguably the most important part in the viral replication cycle.
entry
_________ for entry vary depending on the host cell (animal viruses don’t have to contend with a cell wall structure)
mechanisms
The most common mode of entry int an animal cell is ________ ______ of an enveloped virus.
membrane fusion
Viruses can enter into animal cells through ________ ______ and ___________ of an enveloped or non-enveloped virus.
membrane fusion, endocytosis
Entry into _____ cells depend on damage to tissues and open spots in the cell wall.
plant
These factors can allow for viruses to enter into plant cells:
insects feeding on plants
wind damage
hail/rain damage
fire damage
human-induced damage
Viruses enter into ________ by punching a hole into the cell wall and transferring DNAA through the hole.
bacteria
In _____ replication cycle, phages replicate inside host cells and burst open/lyse them to spread.
lytic
In _________ replication cycles, the phages integrate their genome into the host cell’s genome and is replicated each time the host cell replicates.
lysogenic
When a phage integrates their genome into the bacterial host cells genome, it becomes a ________.
prophage
To cultivate animal viruses, ______ _______ of host cells must be used to grow the targets for the viruses.
tissue culture
