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Microbiology 2ndsem Prelim > Virology > Flashcards

Flashcards in Virology Deck (61)
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1
Q

Soon after interaction with the host cell vision is disrupted infetivity is lost

A

Eclipse period

2
Q

Virus replication cultured only on

A

Monkey kidney cell

Duck egg cell

3
Q

Rhinovirus host receptor

A

ICAM 1

4
Q

HIV host receptor

A

CD4 +T cells

5
Q

Host receptor

Rabies virus

A

ACH receptors

6
Q

Host receptor

HSV 1

A

Fibroblast growth factor receptor

7
Q

Appropriate pH and ionic concentration require counter ion

A

Magnesium ion

8
Q

Refers to the entry of viral particle into the cytoplasm of the host cell

A

Penetration

9
Q

Penetration carried out through

A
Endocytosis ( receptor mediated)
Direct penetration ( viropexis)
Cell fusion ( giant cells )
10
Q

Refers to the physical separation of the viral capsid from the viral genome

A

Uncoating

11
Q

Steps in viral infection

A
Attachment and absorption 
Penetration
Uncoating
Early viral mRNA synthesis
Early viral protein synthesis
12
Q

Infectious nucleic acid

If - stranded virus

A

Non infectious nucleic acid

13
Q

Can bypass the host range specificity provided by the protein host cell receptor interaction

A

Eg poliovirus

14
Q

1st step in gene expression

A

mRNA synthesis

15
Q

DNA viruses except ——- replicate in the nucleus , use host cell DNA dependent RNA polymerase synthesize mRNA

A

Pox virus

16
Q

DNA virus are double stranded

A

Both + and - strands used as templates

17
Q

Doesn’t have access on the RNA polymerase on host cell nucleus

A

Pox virus

18
Q

Pox virus should have RNA polymerase

A

Synthesize mRNA

19
Q

Pox virus replication

A

Cytoplasm

20
Q

RNA viruses are single stranded

A

Can be positive or negative

Used as template can synthesize RNA

21
Q

Positive polarity RNA viruses

A

Picornaviruses
Togaviruses
Flaviviruses

22
Q

Negative polarity

Synthesize own mRNA

A

Orthomyxovirus
Paramyxovirus
Fill virus
Bunyavarius

23
Q

Negative polarity must be converted to positive strand through

A

RNA -RNA dependent mRNA -> transcription

24
Q

2 processes of release

A

Rupture or lysis of cell membrane

Budding through the outer membrane

25
Q

Budding process begin when virus specific proteins enter the cell membrane at specific sites

A

Herpesviruses - nuclear membrane
Pox viruses - inclusion bodies
Coronaviruses - endoplasmic reticulum

26
Q

HIV virus / retro virus

A

Require a DNA intermediate for replication

RNA- DNA-RNA

27
Q

Smallest of all microorganism with size ranging from 20-300nm, smallest of which is

A

DNA virus or parvovirus

28
Q

Smallest RNA virus

A

Picornavirus

29
Q

Largest and most complex

A

Poxvirus (also a DNA virus)

30
Q

Do not have structures that compromise the cell

A

Not cells

31
Q

Almost all viruses are spherical in shape with very few exceptions

A

Rhabdovirus - bullet shaped
Pox virus - brick shaped
Bacteriophage - tadpole t shaped
Tobacco mosaic virus - rod shaped

32
Q

Viruses posses only one type of nucleic acid

A

Either DNA or RNA never both

33
Q

Basis for their classification

A

Nucleic acid

34
Q

They do not have a machinery to produce copies of their own genome. They rely on their host cell for its energy -yielding apparatuses

A

Obligate intracellular parasites

35
Q

Multiply through the process of

A

Replication

36
Q

Viruses doesn’t have

A

Cell wall and ribosomes that ps why antibiotics is not effective

37
Q

Not only viruses can induce interferon production but other bacteria like rickettsia

A

Not virus specific

38
Q

Most of the viruses are haploid, cainta ins one canopy of their genes except

A

Retroviruses that are diploid

39
Q

Composed of nucleic acid , viral genome

A

Core

40
Q

Surround the viral genome

A

Capsid

41
Q

Capsid composed of repeating subunits known as

A

Capsomeres

42
Q

Capsid can assume any symmetry

A

Icosahedral - 20 small triangle

Helical - arranged in hallow coil that appear rod shaped

43
Q

Outside the viral capsid composed of lipoprotein that are derived from the viral host cell membrane

A

Envelope

44
Q

Viruses with envelope

A

Enveloped viruse

45
Q

Virus without envelope

A

Naked viruses

46
Q

Paano mo masasabi na complet e pag naked

A

May nucleic acid

Capsomeres or viral capsid

47
Q

Paano naman kung envelope virus

A

Envelope
Nucleic acid
Capsomeres or capsid

48
Q

Particle that contains the host cell DNA instead of a viral DNA

A

Pseudovirion

49
Q

Particles consist solely of a single molecule of circular RNA without a protein coat or envelope

A

Viroids

50
Q

Infectious protein particles composed solely of proteins

A

Prions

51
Q

Example of prions

A

Mad cow

52
Q

Double stranded DNA except

A

Parvovirus

53
Q

Naked except

A

Herpes
Hepadna
Pox virus

54
Q

Icosahedral symmetry except

A

Poxviruses

55
Q

Replicate in the nucleus of the host cell except

A

Pox viruses which replicate in the cytoplasm of the host cell

56
Q

SS RNA except

A

Reovirus

57
Q

Enveloped except

A

Reovirus

Picornavirus

58
Q

Helical symmetry except

A

Reovirus
Picornavirus
Flavivirus
Togavirus

59
Q

Replicate in the cytoplasm except

A

Orthomyxovirus

Retroviruses

60
Q

Table in family, envelope, symmetry, DNA structure and important viruses

A

Nasa trans

61
Q

Viruses multiply only

A

In living cells