Virology (basics)

Question 1

viral genetics

Define the term

exchange of genes between 2 chromosomes by crossing over within regions of sig bas seq homology

Answer 1

Recombination

Question 2

viral genetics

When viruses with segmented genomes (e.g. influenza virus) exchange segments. High-freq recombination.

Cause world wide influenza pandemics

Answer 2

Reassortment

Question 3

Viral genetics

when 1 or 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.

Answer 3

complementation

Question 4

Viral genetics

Occurs w/simultaneous infection of a cell with 2 viruses. Genome of virus A can be partially or completely coated (forming pseudovirion) w/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 genetic material

Answer 4

Phenotypic mixing

Question 5

Define the 3 types of vaccines

Answer 5

• Live attenuated
• Killed
• Recombinant

Question 6

What does live attenuated vaccine cause taht killed./inactive vacccines dont?

Answer 6

• Live attenuated
  
  • induce humoral + cell mediated immunity
  • but have reverted to virulence on rare occasion
• Killed/inactivated
  
  • induce humoral immunity but are stable

Question 7

give examples of live attenuated vaccines

Answer 7

• Small pox
• Yellow fever
• Chicken pox (VZV)
• Sabin polio virus (UC)
• MMR
• Influenza (intranasal)

Live! One night only! See small yellow chickens get vaccinated with Sabin and MMR! _its inc_redible

Question 8

What is it worth noting about live attenuated vaccines?

• booster req?
• who do you not give it to?

Answer 8

• No booster needed for live attenuated vaccines
• Dangerous to give live vaccines to immunocompromised pts or their close contacts

Question 9

When can MMR be given to HIV pts?

Answer 9

• live attenuated vaccine MMR can be give to HIV patients who do not show signs of immunodeficiency.

Question 10

Name the killed vaccines.

SALK=Killed

RIP Always

Answer 10

• Rabies, Influenza (injected), Salk Polio, and HAV vacccines.

Question 11

Name the 2 recombinant vaccines

Answer 11

• HBV (antigen= recombinant HBsAg),
• HPV (types 6,11, 16, & 18)

Question 12

DNA viral genomes

• all DNA virus are _ _
• expect for Parvoviridae are _ ._
• All are linear except for _ , _ , _ ._

Parvus= small

Answer 12

• dsDNA
• ssDNA
• Papilloma, polyoma, hepadenaviruses (circular)

All are dsDNA (like our cells), except part of a virus (parvovirus) which is ssDNA.

Question 13

RNA viral genomes

• All RNA virus except reoviridae are _ ._
• Positive stranded RNA viuses

Answer 13

• dsRNA
• Retrovirus, togavirus, flavivirus, Coronavirus, flavivirus, hepevirus, calicivirus, picornavirus

I went to a retro (retovirus), toga (togavirus) party, where I drank flavored (flavivirus) Corona (coronavirus), and ate hippy (hepevirus), california (calicivirus) pickles (picornavirus).

Question 14

• Purified nucleic acids of most dsDNA (except poxviruses and HBV) and + strand ssRNa (mRNA) are _ ._
• Naked nucleic acids of neg strand ssRNA and dsRNA viruses are _ ._
  
  • The required _ _ contained in the complete virion.

Answer 14

• infectious
• non-infectious
• polymerases

Question 15

• All DNA viruses replicated in the _ _
  
  • ​ except for _ _
• _​_All RNA viruses replicate in the _ _
  
  • except for _ _& _ _

Answer 15

• nucleus
  
  • poxvirus
• cytoplasm
  
  • influenza virus & retrovirus

Question 16

viral envelopes

Naked (non enveloped viruses included

Give PAPP smears and CPR to a naked Heppy

Answer 16

• DNA
  
  • Papillomavirus
  • Adenovirus
  • Parvovirus
  • Polymavirus
• RNA
  
  • Calicivirus
  • Picornavirus
  • Reovirus
• Heppy
  
  • Hepevirus

Question 17

viral envelopes

• Enveloped viruses acquire their envelopes from _ _ when they exit the cell.
• Exceptions include herpesvirus, which acquire envelopes from _ _.

Answer 17

• plasma membrane
• nuclear membrane

Question 18

all DNA viruses

are HHAPPPPy viruses

Answer 18

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

Question 19

All DNA virues are

Double stranded except:

Answer 19

parvovirus (single stranded)

Question 20

All DNA viruses are linear except for (3)

Answer 20

• Papilloma, polyoma (circular, supercoiled)
• Hepadna (circular incomplete)

Question 21

All DNA viruses

are icoshedral except:

Answer 21

poxvirus

Question 22

All DNA viruses

replicated in the nucleus except _ _

(and why can it replicated outside of nucleus?)

Answer 22

pox (carries own DNA dependent RNA polymerase)