GENETICS OF VIRUSES

The Basics• Compare the size!• Two basic components:– A diverse genome• ssDNA• dsDNA (Smallpox)• ssRNA (Measles)• dsRNA

– Capsid/Envelope

Viral Structure

Obligate Intracellular Parasites?• Host range varies with

virus– Swine flu vs. smallpox

• Tissue specific– Cold virus to AIDS virus• What determines the

limits to the host range?

Lytic Cycle• The “virulent” phage• Why are bacteria not extinct?

Lysogenic Cycle• The “temperate” phage• How is the prophage involved?

Viral Envelopes

• Describe the steps:• How does Herpes

virus differ?

Retrovirus• HIV

Vaccines• How do they work?• Why can’t viruses be

treated with antibiotics?• Eradication of viral

diseases…how is this possible?– Smallpox (1976)

Emerging Viruses• Why are some example?• Why are they typically RNA

viruses?• Why do they spread?

Plant Viruses

Viroids & Prions