Viral classification

Question 1

What are the seven families of double stranded DNA viruses?

Answer 1

1. Poxviridae
2. Asfaviridae
3. Iridoviridae
4. Herpesviridae
5. Adenoviridae
6. Papillomaviridae
7. Polyomaviridae

Question 2

What are the two families of single stranded DNA viruses?

Answer 2

1. Parvoviridae
2. Circoviridae

Question 3

What DS DNA viral family is complex-shaped (no symmetry), enveloped, and has linear DNA? Where do these replicate?

Answer 3

Poxviridae

Replicate in cytoplasm (“viroplasm”) and are released by budding

Question 4

What are the two subfamilies of poxviridae? To which do vaccina virus (human/animal) and Orf virus (sheep/goats) belong?

Answer 4

1. Chodropoxvirinae
   
   • Vaccina and Orf virus belong to this subfamily
2. Entomopoxvirinae
   
   • infect insects

Question 5

What virus family has members with DS linear DNA and an enveloped spherical structure with icosohedral symmetry?

What is the only genus within this family and what disease is the family named after?

Where does it replicate?

Answer 5

Family: Asfaviridae
Genus: Asfavirus
African Swine Fever virus (pigs)

Replication in cytoplasm and nucleus

Question 6

What viral family, named after iridescence, has members with linear DS DNA, icosahedral symmetry and an envelope?

Answer 6

Iridoviridae

Question 7

What are the three genera in the family Iridoviridae?

Answer 7

1. Ranavirus (frogs)
2. Lymphocystivirus
3. Goldfish virus 1

Question 8

What order contains three families, has DS, linear DNA, is enveloped, and has an icosahedrally symmetry nucleocapsid surrounded by tegument?

Answer 8

Herpesvirales

Question 9

What are the three viral families in order Herpesvirales and what organisms does each family infect?

Answer 9

1. Herpesviridae
   
   • Herpesviruses of mammals, birds, and reptiles
2. Alloherpesviridae
   
   • Herpesviruses of fish and frogs
3. Malacoherpesviridae
   
   • Herpesviruses of oysters and Abalonies

Question 10

What viral family has linear, DS DNA, is non-enveloped, and has icosahedral symmetry? What diseases is it responsible and what animals do they infect?

Answer 10

Adenoviridae

Human, equine & canine, avian, ovine, frog adenovirus

(Chicken) egg drop syndrome

Question 11

What two families share the properties of having circular DS DNA, icosahedral symmetry, and being non-enveloped?

What common STD is in one of these families?

Answer 11

Papillomaviridae and Polyomaviridae

HPV - human papillomavirus

Question 12

What viral family has members with linear negative or negative/positive sense SS DNA, that are non-enveloped, have icosahedral symmetry, and replicate in nucleus of cells in S phase of cell cycle?

Answer 12

Parvoviridae

Question 13

What are the two subfamilies within family Parvoviridae and which infects mammalian hosts?

Answer 13

1. Parvovirinae
   
   • infects mammals, e.g. Feline & canine parvovirus
2. Densovirinae
   
   • no mammalian hosts, mainly insects

Question 14

Which group of parvoviruses need co-infection with the other viruses like Adenoviruses for their replication?

Answer 14

Adeno-associate viruses (AAV)

Question 15

What viral family has members with circular negative or negative/positive sense SS DNA, that are non-enveloped, have icosahedral symmetry, replicate in nucleus of cells in S phase of cell cycle, and are the smallest of all viruses?

Answer 15

Circoviridae

Question 16

What are two genera within the family Circoviridae and what are some diseases they cause?

Answer 16

1. Circovirus
   
   • Porcine circovirus 1
2. Gyrovirus
   
   • Chicken anemia virus

Question 17

What are the two families of reverse transcribing viruses?

Answer 17

1. Hepadnaviridae
2. Retroviridae

Question 18

What viral family has members with enveloped virions, icosahedral symmetry, Circular DNA, partially double stranded and single stranded, where the virus encodes reverse transcriptase (RT) for conversion of RNA to DNA?

What diseases do these cause?

Answer 18

Hepadnaviridae

e.g. hepatitis B virus (human), duck hepatitis B virus

Question 19

What viral family has members with enveloped virions, icosahedral nucleocapsid symmetry, diploid, positive sense, linear, ssRNA, contain reverse transcriptase (RT), and bud from the plasma membrane?

Answer 19

Retroviridae

Question 20

Retroviruses are the common causes of which (four) types of infections and disorders in human and animals?

Answer 20

1. Cancers
2. Slow infections
3. Immunologic disorders
4. Neurodegenerative conditions

Question 21

What are the most common kinds of cancers caused by retroviruses?

Answer 21

• Human T-cell lymphotropic virus type 1 (HTLV-1) causes adult T-cell leukemia (ATL)
• The most common retroviral tumors in animals are:
• Bovine leukemia virus
• Avian leukosis
• Koala retrovirus

Question 22

What are two common slow viral conditions caused by retroviruses?

Answer 22

– Human Immunodeficiency virus (HIV)

– Equine infectious anemia

Question 23

What are two neurodegenerative conditions caused by retroviruses?

Answer 23

• HTLV-1 causes myelopathy/tropical spastic paraparesis (HAM/TSP).
• Visna-Maedi virus causes encephalitis and chronic pneumonitis in sheep

Question 24

What are the two families of dsRNA viruses?

Answer 24

• Reoviridae
• Birnaviridae

Question 25

What are the **14 families** of **ssRNA** viruses?

Answer 25

* Paramyxoviridae * Rhabdoviridae * Filoviridae * Bornaviridae * Orthomyxoviridae * Bunyaviridae * Arenaviridae * Coronaviridae * Arteriviridae * Picornaviridae * Caliciviridae * Asteroviridae * Togaviridae * Flaviviridae