Flashcards in Viruses Deck (55)
The virus genome typically consist of____-_____ bases or base pairs
protein subunits that make up the capsid and determine the shape of the virus
What shapes can viruses be in?
Helical (ex. tobacco mosaic virus)
Polyhedral (ex. adenoviruses)
Combination of the both (ex. bacteriophages or phages)
The____consist of a polyhedral head and a helical tail with tail fibers that attach to a host cell.
surrounded by an outer envelope of plasma membrane derived from the host cell. ex. HIV
Enveloped viruses produce envelope proteins that extend out from the envelope as_____, which interact with the host cell
Viruses can be classified based on what?
Presences of an envelope
Method of transmission
_______is based on the type of nucleic acid the virus contains, and how mRNA is produced.
Baltimore Classification System
Bacteriophages typically consist of what?
long nucleic acid molecule (usually dsDNA) coiled in a polyhedral head, and a tail that functions in penetration of the host
List the 2 types of viral reproduction
In a lytic cycle the virus______the host cell
Viruses that have only a lytic cycle are what?
virulent menaing they cause disease and sometimes death
List the 5 steps to the lytic reproduction
Replication and synthesis
When a virus penetrates the host it may what?
completely enter or only the nucleic acid may enter
Newly synthesized viral components are assembled into new viruses
What type of viruses do not always destroy there host?
What happens in the lysogenic cycle?
the viral genome usually becomes part of the host DNA and is reproduced along with it
What is another name for host bacterial DNA?
_____genes may be repressed indefinatly or be triggered by external conditions to go into the lytic cycle
bacterial cells containing certain temperate viruses may exhibit new properties
Give an example of lysogenic conversion
The bacterium Corynebacterium diphtheria only causes diptheria if infected by a specific temperate phage whose DNA codes for the diptheria toxin
Viral infections do not usually kill plants, but rather___
change leave shape
cause spots and streaks
Most plant viruses have______, but not______.
The genome of most plant viruses consist of_____
What is the carrier of plant viruses?
Plant viruses can be genetic
How does a virus spread through a plant?
What are some things viruses cause
How many viruses a year do humans usually get?