1. VIRUSES What kingdom are viruses found in?______________________
Are they living or non-living? Explain.
none
Non-living because they require a host to reproduce
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2. A Typical Virus Some general information about viruses
All viruses are ____________ and therefore require a host organism for its survival and continued reproduction.
Viruses only infect in their ___________________.
Viruses that infect bacteria are called ____________________.
All viruses act by forcing the host cell to manufacture 100’s or 1000’s of copies of itself. While this is going on, the host cell can’t make the material it needs to carry out its normal function – an _____________ results. If the infection spread locally an _____________ occurs, and if it travels globally it creates a ___________ .
Some viruses contain RNA instead of DNA. RNA viruses cause the more serious diseases.
Ex: DNA virus diseases_______________________
Ex. RNA virus diseases _______________________
A Typical Virus
nonliving
host range
capsid
DNA
bacteriophage or phage
sheath
infection
epidemic
pandemic
tail
hepatitis B, cold sores, chicken pox, tumours, etc.
measles, mumps, polio, the cold, HIV, rabies
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3. Phage attaches itself to host cell Phage injects its DNA into the host
Phage reproduce either one of two ways:
Lytic Cycle - the virus ___________________________________________________
Lysogenic Cycle - the virus ___________________________________________
completely destroys the host cell
does not immediately destroy the host cell, virus enters a dormant state
TYPE A: Lytic Cycle - the host cell is completely destroyed (________________)
- reproduction can occur rapidly (_________________)
- In animal cells the _______________ enters the host
lysis
< 1 hour
entire virus
Phage attaches itself to host cell
Phage injects its DNA into the host
Phage DNA instructs host to make more phage DNA and capsids
New phage are assembled inside the host cell
Host cell fills with phage and fluid and bursts = lysis
Several hundred new phage are released and seek out uninfected cells
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4. - viral DNA remains dormant inside host cell
TYPE B: Lysogenic Cycle - the host cell is not destroyed (lysed) immediately
- viral DNA remains dormant inside host cell
- In animals, the entire virus remains dormant in the host cell for _______________ Ex. ______________________.
months to years
Herpes, HIV
Phage attaches to host cell and injects DNA
Phage DNA becomes part of host cell’s DNA by recombination
Host cell reproduces normally and copies the phage DNA
Eventually phage DNA breaks away and instructs the cell to make new phage DNA and capsid
New phage form, cell lyses, phage are released.
Review 
Define: Vaccination, Transduction, types of Gene Therapy, Viroids, Prions, BSE, CJD.
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