General properties of Virus

Question 1

Parts of the virus

Answer 1

Nucleocapsid- Nucleic acid + capsid (protein coat covering it)
Tegument- proteinaceous structure between capsid and envelope
Envelope- Lipid containing membrane surrounding virus
Peplomers- virus encoded glycoproteins on outer surface as projections

Question 2

Father of virology

Answer 2

Martinus beijerinck
Proposed contagium vivum fluidum (living infectious fluid) when studying mosaic disease in Tobacco mosaic plant

Question 3

1. Largest DNA virus
2. Largest RNA virus
3. Smallest DNA virus
4. Smallest RNA virus

Answer 3

1. Pox virus
2. Filovirus
3. Parvovirus
4. Picornavirus

Question 4

All DNA viruses are double stranded except

Answer 4

Parvovirus
(single stranded DNA)

Question 5

All RNA viruses are single stranded except

Answer 5

Reovirus- dsRNA virus
Retrovirus- 2 copies of ssRNA

Question 6

Enveloped virus characteristics

Answer 6

Bile sensitive
Heat labile
Ether sensitive
Pleomorphic

Non enveloped is opp of this

Question 7

Lipid of enveloped virus is ____ origin and protein is _____ coded

Answer 7

Host cell origin
virus coded

Question 8

Non enveloped DNA viruses

Answer 8

Adenovirus
Parvovirus

Question 9

Non enveloped RNA viruses

Answer 9

‘PARCH-a-eee’
Picornavirus
Astrovirus
Reovirus
Calcivirus
Hep A and E

Question 10

Enveloped DNA viruses

Answer 10

‘HHP’
Herpes
Hep B
Poxvirus

Question 11

Enveloped RNA virus

Answer 11

‘Hey Ruby, check Dengue’s Japanese Kite Zooming’

Hep C
Rubella
Chikungunya
Dengue
Japanese Enceph virus
Kyasanur forest disease virus
Zika virus

Question 12

What is solvent/ detergent plasma?

Answer 12

aka SD plasma
made from plasma collected from may people and then processed with solvents in an attempt to remove viruses

Question 13

What is segmented genome?

Answer 13

A genome divided into multiple pieces with intact genes so these can be exchanged between related viruses

This recombination is called Reassortment. It forms unique chimeric genome which results in evolved virus with increased fitness

It can be responsible for antigenic shifts

Question 14

Examples of segmented viruses

Answer 14

‘ARBO’
Arenavirus- 2 segments
Rotavirus- 11 segments
Bunyavirus- 3 segments
Orthomyxovirus- 8 segments

Question 15

Molluscum contagiosum is a part of ____ family

Answer 15

Poxviridae

Question 16

All DNA viruses have replication process in ____ except ______ (which is in cytoplasm)

Answer 16

Nucleus except Poxvirus (which is in cytoplasm)

Question 17

All RNA viruses have replication in _______ except ________ which is in nucleus

Answer 17

Cytoplasm
Orthomyxovirus, Retrovirus

Question 18

What is a negative stranded RNA

Answer 18

ssRNA with 3’-5’ RNA is a negative strand RNA

Question 19

What does negative strand RNA use to replicate?

Answer 19

RNA replicase/ RNA dependent RNA polymerase

Question 20

Examples of negative stranded RNA viruses

Answer 20

‘Always Bring Da Polymerase OR Fail to Replicate’
Arenavirus
Bunyavirus
Deltavirus
Paramyxovirus
Orthomyxovirus
Filovirus
Rhabdovirus

Question 21

Ebola virus is spread by

Answer 21

Direct contact with infected body fluids

Question 22

Ebola virus

Answer 22

Filamentous virus
single stranded RNA

Question 23

Shape of
1. Adenovirus
2. Tobacco mosaic virus
3. Poxvirus

Answer 23

1. Space ship
2. Rod shaped
3. Brick shaped

Question 24

COVID 19 symmetry

Answer 24

Enveloped helical symmetry

Question 25

Naked icosahedral viruses example

Answer 25

Adenovirus Poliovirus Hep A

Question 26

Enveloped helical viruses examples

Answer 26

Coronavirus Influenza Parainfluenza Rabies Mumps Measles

Question 27

Complex structure of virus seen in

Answer 27

Pox virus

Question 28

Study of viral symmetry by electron microscopy requires use of ____ stains for example ____.

Answer 28

Heavy metal stains Eg. Potassium phosphotungstate It is a form of negative staining

Question 29

Most efficient symmetry

Answer 29

Icosahedral

Question 30

Icosahedron has ___ faces and __ vertices

Answer 30

20 12

Question 31

Why is it not possible for empty helical particles to form?

Answer 31

Periodic interactions are required between capsid protein and nucleic acid for stable helical symmetry

Question 32

Enveloped icosahedral symmetry shown by

Answer 32

Herpes Yellow fever virus Rubella virus

Question 33

Allantoic cavity inoculation is done for growth and replication of ___ virus

Answer 33

Influenza, Mumps Amniotic cavity also used but its difficult to access

Question 34

Yolk sac inoculation of virus for growth and replication is done for

Answer 34

Herpes simplex virus It can also be grown in Chorioallantoic membrane

Question 35

Chorioallantoic membrane inoculation is done for ____ virus growth

Answer 35

HSV, Poxvirus

Question 36

Suckling mice inoculation is done for growth of ___ viru

Answer 36

Coxsackie Arbovirus

Question 37

Types of tissue lines with examples

Answer 37

Primary cell lines: 1. Rhesus kidney cell line, 2. Human amniotic cell line, 3. chick embryo fibroblast Secondary cell lines: 1. Human fibroblast cell line 2. MRC-5 3. WI-38 Continuous cell lines: 1. HeLa cell lines 2. HEp-2 3. Vero 4. KB

Question 38

Methods of assay of infectivity of viruses

Answer 38

Physical Biological

Question 39

Physical methods of assay of infectivity of viruses

Answer 39

They can estimate total viral count They cannot differentiate between infectious and non infectious viral particles Examples; RT-PCR, Electron microscopy, Antigen detection assay

Question 40

Biological methods for assay of infectivity of viruses

Answer 40

They can estimate total viral count and can detect infectious virus Eg: Qualitative- endpoint biological assay Quantitative- plaque and pock assay

Question 41

Cytopathic effects caused by viruses means

Answer 41

Morphological changes in cells that are caused by viruses is called cytopathic effects. These viruses are called Cytopathogenic viruses. They can be detected by light microscope

Question 42

Examples of cytopathogenic viruses

Answer 42

Rapid crenation and degeneration of cells by Enterovirus Synctitium/ Multinucleated giant cell formation by Measles, Mumps, RSV Discrete focal degeneration by HSV Large granular clumps resembling grapes by Adenovirus Vacuolation of cytoplasm by Simian virus 40