Prokaryotes and viruses

• What are viruses classified as?

  Non-cellular infectious particles
• How do viruses straddle the boundary between living and non-living?

  They exhibit characteristics of both categories
• What is the size range of viruses compared to prokaryotic cells?

  20 to 300 nm
• What are the main structural components of viruses?

  Nucleic acid core, capsid, and envelope
• What types of nucleic acids can be found in viruses?

  DNA or RNA
• What is the function of the capsid in a virus?

  It protects the viral nucleic acid
• What is an envelope in the context of viruses?

  An outer layer formed from cell membrane lipids
• How do viruses reproduce?

  By infecting living cells and using their machinery
• What do all viruses have in common regarding their reproduction?

  They are all parasitic
• What do viruses use from host cells to produce new viral particles?

  Their protein-building machinery (ribosomes)
• What distinguishes viruses from prokaryotes and eukaryotes?

  • Viruses are non-cellular
  • They cannot reproduce independently
  • They rely on host cells for replication