Virology I

• What is the conversion factor between micrometers and nanometers?

  1 𝛍m = 1000 nm
• What are viruses classified as in terms of size?

  One of the smallest microorganisms

  
• What does the Latin word 'Virus' mean?

  Toxin or poison
• What type of diseases can Herpes Simplex Virus cause?

  Severe acute oral and oro-facial disease
• How can viruses be transmitted in a dental setting?

  Between patients and dental staff
• What are the main features that characterize viruses?

  • Nucleic acid core with viral genome
  • Surrounded by a protein shell (capsid)
  • Structure referred to as nucleocapsid

  
• What is the size range of viruses?

  10-100 nm
• What type of genetic material do viruses have?

  Either DNA or RNA, never both

  
• Why are viruses considered obligate intracellular parasites?

  They can only multiply inside living cells
• What is the structure of a virus's capsid?

  • Composed of repeating protein units
  • Visualized as capsomeres under electron microscopy

  
• What is the difference between naked and enveloped viruses?

  Naked viruses lack a lipid envelope

  
• What are peplomers in enveloped viruses?

  Protein units visualized as spikes

  
• What is the major bulk of a virion composed of?

  Protein that protects the nucleic acid
• What is the role of viral surface proteins?

  They bind to receptors on susceptible cells
• What are the three kinds of symmetry in viral nucleocapsids?

  1. Icosahedral symmetry
  2. Helical symmetry
  3. Complex symmetry

  
• What type of viruses are Papovaviruses?

  Small, icosahedral DNA viruses

  
• What diseases can Papillomavirus cause?

  Benign skin tumors and oral cancers
• What is the significance of adenoviruses?

  Commonly associated with respiratory infections
• What is the largest virus that infects humans?

  Poxviruses
• What is the historical significance of smallpox?

  It has been eradicated since 1980
• What is the mode of transmission for HepaDNAviruses?

  Via blood and saliva

  
• What type of nucleic acid do Parvoviruses have?

  Single-stranded DNA
• What are the three major subgroups of Human enteroviruses?

  Polioviruses, Echoviruses, Coxsackieviruses
• What is the significance of Orthomyxoviruses?

  Includes Influenza A viruses
• What are the four common human pathogens in Paramyxoviruses?

  Measles, Mumps, Parainfluenza, RSV
• What is the characteristic of Coronaviruses?

  Petal-shaped surface projections
• What are the common symptoms of SARS-CoV-2 infection?

  Mild upper respiratory infections or severe illness
• What is the unique feature of Retroviruses?

  Viral RNA is transcribed into DNA
• What are the general steps in the viral replication cycle?

  1. Adsorption
  2. Penetration
  3. Uncoating & Eclipse
  4. Transcription
  5. Synthesis of viral components
  6. Assembly
  7. Release of virions

  
• What are viroids and their characteristics?

  Naked RNA causing plant diseases
• What are prions?

  Agents of chronic diseases, not viruses
• What does the term "hepatitis" refer to?

  Inflammation of the liver
• What are the six types of hepatitis viruses?

  1. Hepatitis A
  2. Hepatitis B
  3. Hepatitis C
  4. Hepatitis D
  5. Hepatitis E
  6. Hepatitis G

  
• Why can a person be infected with multiple types of hepatitis viruses?

  They are unrelated to each other

  
• What are the chronic effects of HBV and HCV infections?

  Leading causes of cirrhosis and cancer
• What is the diameter of Picornaviruses?

  ~28 nm
• What is the global impact of hepatitis B infection?

  Over 1 million deaths worldwide
• What is the causative agent of infectious hepatitis?

  Hepatitis A virus (HAV)
• What is the transmission route for HAV?

  Mainly fecal-oral route
• What happens after HAV ingestion?

  It enters the bloodstream and targets the liver