A 2.3 Viruses Flashcards
What are the three common structural features that apply to all viruses?
Non-living, non-cellular, and multiple origins
What are the 6 stages in the lytic cycle?
- Attachment
- Penetration
- DNA replication
- Transcription
- Translation and Assembly
6.Lysis
Why do lytic viruses find new hosts?
When the virus reproduces it bursts through the host cell and kills it
What are the different types of viruses?
Helical, Polyhedral, spherical, and complex
In which organisms is the lytic cycle most common?
Animals and Plants
What are the 4 stages of the lysogenic cycle?
1.Attachment
2.Penetration
3.Intergration
4.Cell division
What are the two features of the lysogenic cycle?
Doesn’t kill its host and id undetectable.
What are the two hypothesis for virus origin?
Progressive and Regressive
What is the progressive hypothesis?
Viruses evolved from modified cell components
What is the regressive hypothesis?
Viruses evolved from loss of cell components.
What does the amount of mutations in viruses cause?
Lots of variation
What is the main reason for rapid evolution in viruses?
Short generation time
What does natural selection favour?
Viruses that can evade detection and destruction.
What are antigens?
Proteins in the virus surface used for attaching to host cells
Why are the two main reasons for virsuses being hard to treat?
Drug resistance and evasion of immune systems.
