Download Mic - Viruses Review

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Viruses - Review
Directions: In each space below, fill in the term described.
1. The protein coat of a virus is known as a ___capsid___.
2. Viral DNA that is integrated into a bacterial chromosome is a ___prophage___.
3. The bursting of a host cell is also called ___lysis____.
4. Viruses can be classified according to which genetic material, __DNA__ or ___RNA__, makes up the viral
core.
5. Early viral studies were done with the __tobacco__ ___mosaic___ virus.
6. Viruses are much __smaller__ than bacteria in size.
7. RNA viruses are also called ____retroviruses___.
8. Some viruses have an outer ___coating___ that helps them enter their host cell.
9. Temperate viruses reproduce via the __lysogenic__ cycle.
Directions: Answer the following.
1. What are the two main parts of a virus?
• capsid
• nucleic acid core
2. What is a bacteriophage?
Answer - A virus that affects bacterial cells
3. What is the scientific proofs that viruses are not living organisms?
Answer – unable to reproduce without a host and not composed of cells.
4. At what point in the reproductive cycle of the T4 Bacteriophage is host cell infection irreversible?
Answer – once the nucleic acid has been injected into the cell.
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Directions: Look at the diagram below showing the lytic cycle of the T4 Bacteriophage. Provide a term that
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describes what is happening at each numbered stage.
Answer – 1. – recognition
2. – insertion
3. – replication
4. – assembly
5. - lysis
Directions: Compare and contrast.
1. Lytic cycle and Lysogenic cycle
• same in that they are both
Answer – cause replication and assembly of viral particles, resulting in cell lysis.
• different in that
Answer – lytic cycle the process starts immediately and lysogenic the process is halted for a time and a
prophage forms.
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