Virus- Taxonomy/Basics

Question 1

Name the only ssDNA viral genome:

Answer 1

Parvovirus

Question 2

Name the only DNA virus that replicates in the cytoplasm:

Answer 2

Poxviridae (carries its own DNA-dependent RNA polymerase)

Question 3

Name the only dsRNA viral genome:

Answer 3

Reoviruses (eg, rotavirus)

Question 4

Name the family of the smallest RNA viruses:

Answer 4

Picornaviruses

Question 5

Name four families of naked RNA viruses:

Answer 5

CRAP:

1. Calicivirus
2. Reovirus
3. Astrovirus
4. Picornavirus

Question 6

Name six medically important DNA viral families:

Answer 6

HHAPPPy:

1. Hepadnaviridae
2. Herpesviridae
3. Adenoviridae
4. Poxviridae
5. Parvoviridae
6. Papovaviridae

Question 7

Name two families of circular DNA viruses:

Answer 7

1. Papovaviridae

2. Hepadnaviridae

Question 8

Name three naked DNA viruses:

Answer 8

PAP:

1. Parvo
2. Adeno
3. Papov

Question 9

Name two families of RNA viruses that do not replicate solely in the cytoplasm:

Answer 9

1. Influenza viruses

2. Retroviruses

Question 10

Where do most enveloped viruses acquire their membranes?

Answer 10

From plasma membrane (except herpesviruses—nuclear membrane)

Question 11

Name four families of segmented viruses:

Answer 11

BOAR (all RNA viruses)

1. Bunyaviridae
2. Orthomyxoviridae (influenza viruses)
3. Arenaviridae
4. Reoviridae

Question 12

Name the only diploid viruses:

Answer 12

Retroviruses

Question 13

What types of nucleic acids do not require special enzymes to be infectious?

Answer 13

Those with same structure as host nucleic acids (eg, positive-stranded ssRNA and most naked dsDNA)

Question 14

The virus contains its own genetic material but is coated with surface proteins from another virus, which determine its inf ectivity

Answer 14

Phenotypic mixing

Question 15

Occurs when viruses exchange segments of their genomes

Answer 15

Reassortment

Question 16

Occurs when a nonmutated virus assists a mutated one by making a functional gene product that serves both itself and the mutated virus

Answer 16

Complementation

Question 17

Exchanging oligonucleotides by crossing-over within base sequences

Answer 17

Recombination

Question 18

What type of antigenic change in the influenza virus causes epidemics?

Answer 18

Antigenic drift (minor changes from random mutation)

Question 19

What type of antigenic change in the influenza virus causes pandemics?

Answer 19

Antigenic shift (reassortment of genome, including animal acquisition) 
(Drifting is a Slow Process, Shifting is a Rapid Process)

Question 20

For each of the following vaccines, state whether it is live attenuated or killed:

Sabin Polio

Answer 20

Live attenuated

Question 21

For each of the following vaccines, state whether it is live attenuated or killed:

Salk Polio

Answer 21

Killed (SalK = Killed)

Question 22

For each of the following vaccines, state whether it is live attenuated or killed:

May revert to virulence

Answer 22

Live attenuated (very rare)

Question 23

For whom is it dangerous to receive live vaccines?

Answer 23

Immunocompromised hosts (ie, transplant recipients, AIDS patients, and pregnant women)