Microbial Models: The Genetics of Viruses and Bacteria
Campbell Chapter 17

1. What forms can a viral genome take?

2. Distinguish between a capsid and an envelope.

3. What is meant by host range?

4. Describe the lytic and lysogenic cycles.

5. Scientists have discovered how to put together a bacteriophage with the protein coat of phage T2 and the DNA of T4. If this composite phage were allowed to infect an E. coli, then phages produced by this cell would have what type of DNA and what type of protein? Of what use is an envelope to a virus?

6. What is a retrovirus?

7. What is a viroid?

8. What is a prion?

9. How might viruses have originated?

10. What is transformation?

11. A microbiologist found that some bacteria infected by a particular phage had developed the ability to produce a particular enzyme which they could not make before they were infected. Why did this occur? What is the term used for this phenomenon?

12. Describe conjugation.

13. What is a plasmid?

14. What are transposons?

15. Describe the basic concept of the operon.

16. Carefully explain the role of the following in the lactose operon of E. coli:
a) promoter
b) regulator
c) operator
d) structural gene
e) repressor protein

17. Explain how the lac and trp operons differ.