Viral replication and taxonomy

Question 1

What are the four components used to classify viruses?

Answer 1

1) Nucleic acids
2) Capsid
3) Envelope
4) Size

Question 2

What are the 7 DNA viruses?

Answer 2

HHAPPP:

Herpes, Hepadna, Adeno, Pox, Parvo, Papilloma, Polyoma

Question 3

All DNA viruses are double stranded except?

Answer 3

Except parvo (very simple little guy!).

Question 4

All DNA viruses replicate in nucleus except?

Answer 4

Pox (very complicated! carries its own DNA-dependent RNA polymerase).

Question 5

All DNA viruses are icosahedral except?

Answer 5

Pox (complex, big guy). Pox in a box!

Question 6

All DNA viruses are linear except?

Answer 6

Hepadna (circular, incomplete)

Papilloma and polyoma

Question 7

All DNA viruses are enveloped except?

Answer 7

Gotta be NAKED to get a PAPP:

Papilloma, Adeno, Polyoma, Parvo

Question 8

All RNA viruses are single stranded except?

Answer 8

Reoviridae are double stranded.

Question 9

Which RNA viruses are naked?

Answer 9

“CPR to the naked Hippy!”

Calici, Picornia, Reo, Hepe

Question 10

Which RNA viruses are icosahedral?

Answer 10

Ds: Reo

+single stranded: Picorna ,Calici, Toga, Flavi,

Question 11

Which RNA viruses replicate in the nucleus?

Answer 11

Retro and influenza/orthomyx

Question 12

Which enveloped viruses acquired its virus from NUCLEAR membrane instead of plasma membrane?

Answer 12

Herpesvirus.

Question 13

What is viral genetic “recombination”

Answer 13

Exchange of genes between 2 chromosomes by crossing over within regions of significant base
sequence homology.

Question 14

What is viral genetic “reassortment”?

Answer 14

When viruses with segmented genomes (e.g., influenza virus) exchange genetic material.

Question 15

What is viral genetic “complementation”?

Answer 15

When 1 of 2 viruses that infect the cell has a mutation that results in a nonfunctional protein. The
nonmutated virus “complements” the mutated one by making a functional protein that serves
both viruses.

Question 16

What is a classic example of viral genetic complementation?

Answer 16

hepatitis D virus requires the presence of replicating hepatitis B virus
to supply HBsAg, the envelope protein for HDV.

Question 17

What is viral phenotypic mixing?

Answer 17

Occurs with simultaneous infection of a cell with 2 viruses. Genome of virus A can be partially or completely coated (forming pseudovirion) with the surface proteins of virus B. Type B protein coat determines the tropism (infectivity) of the hybrid virus. However, the progeny from this infection
have a type A coat that is encoded by its type A genetic material.

Question 18

Which vaccinations are live attenuated?

Answer 18

Vaccines for bebes/kids: rotavirus, MMR, chickenpox
Vaccines for everyone: influenza (intranasal)
Vaccines for Scary stuff: smallpox, Sabin’s polio, yellow fever

Question 19

Which vaccinations contain killed virus?

Answer 19

RIP, Alaska (AK).

Rabies, Influenza (IM), SalK Polio, and Hep A vaccines

Question 20

What vaccinations contain a subunit?

Answer 20

HBV (antigen HBsAg), HPV (6,11,16,18)

Question 21

Which RNA viruses are + single stranded?

Answer 21

I went to a retro toga party in California where I drank Corona with hippies and ate flavored pickles. (7 viruses)

Retrovirus, togavirus, Calicivirus, coronavirus, hepevirus, flavivirus, and picornavirus

Question 22

Which nucleic acids are infectious when isolated?

Answer 22

Those belonging to most dsDNA and + strand ssRNA viruses. Exceptions: poxvirus and HBV.

Question 23

Which nucleic acids are generally not infectious when isolated? Why not?

Answer 23

Those belonging to neg strand ssRNA and dsRNA. They need polymerases that come with them in the complete virion.

Question 24

Which RNA viruses are segmented?

Answer 24

Bunyavirus, Orthomyxo, arenaviruses, and Reoviruses