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Flashcards in Virus Classification Deck (29):
1

how is a virus different from a bacterium

Virus can NOT replicate w/out a host
-bacteria replicate autonomously

2

how is a virus different from a toxin

Virus CAN replicate inside a host
-toxin can not replicate

3

what is a bacteriophage

it is a virus that attacks then replicates inside a bacteria

4

T/F Bacteria are smaller than viruses ?

F - virus are smaller from 18-300 um

5

What are the two theories of Virus Origin

-Cellular origin - viruses were once cellular components and evolved separate over time
-Autopoietic Origin - viruses were originally their own independent entities and evolved to become dependent on other cells for replication

6

What are the 5 ways to classify a virus

-virus particle structure (main)
-genome (main)
-replication features (main)
-serology
-stability

7

using virus particle structure to classify a virus takes into account what 3 characteristics

-composition
-size
-shape

8

what is a nucleocapsid

RNA or DNA core protected by a capsid

9

what is a capsid

a virus' protein coat

10

a virus is defined by its ______ structure

nucleoplasmid

11

nucleocapsids are composed of individual repeating protein subunits called ?

capsomeres

12

A virus particle structure may have envelopes, what are they ?

its a virus-modified cellular membrane

13

what are some disadvantages of an envelope

very susceptible to many lab solvents

14

what are the different types of genomes that a virus can have that help to classify viruses

DNA - single or double
RNA - single or double
----(+) sense ssRNA
-----(-) sense ssRNA

15

what is the difference b/w (+) sense ssRNA and (-)sense ssRNA

(+)sense ssPNA is ready to be used to make proteins whereas (-)sense ssRNA must transcribe first

16

in order for replication to start in ssDNA, what specific structure must be formed

ssDNA hairpin

17

in order for replication of dsDNA to start, what structure must be formed

dsDNA rolling circle

18

in order for a RNA virus to start replication, what does it require that a DNA virus does not

RNA dependent RNA polymerase

19

what type of viral genome needs access to the nucleus to start replication

DNA virus

20

what type of viral genome requires a RNA dependent RNA polymerase in order to start replication

RNA virus

21

what is the major factor of eradication of a virus

host range (tropism)
-easier to eradicate if only infect human hosts
-hard to eradicate if host range is all mammals

22

what is the major determinent of a virus' host range (tropism)

attachment

23

which needs an RNA dependent RNA polymerase in order to start replication,
(+) sense ssRNA or (-) sense ssRNA

(-)sense ssRNA

24

all virus/ rely on what host organelle to produce their own viral proteins ?

ribosomes cuz virus have NONE

25

What are the 3 ways of release after replication that help classify viruses

-Lysis
-weak lysis
-Budding

26

what specific type of viruses are released via budding

enveloped viruses

27

when examining the replication kinetics of viruses, what type of growth curves are used

one step growth curves

28

T/F viruses are obligate intracellular parasites

T

29

when are virus' considered "alive"

when they are inside the cells