Guiding Questions
mcourtney 21 Jan 2008 09:45
The Genetics of Viruses
- Recount the history leading up to the discovery of viruses. Include the contributions of Adolf Mayer, Dimitri Ivanowsky, Martinus Beijerinck, and Wendell Stanley.
- List and describe the structural components of viruses.
- Explain why viruses are obligate intracellular parasites.
- Explain how a virus identifies its host cell.
- Describe bacterial defenses against phages.
- Distinguish between the lytic and lysogenic reproductive cycles, using phage lambda as an example.
- Describe the reproductive cycle of an enveloped virus. Explain the reproductive cycle of the herpesvirus.
- Describe the reproductive cycle of retroviruses.
- List some characteristics that viruses share with living organisms and explain why viruses do not fit our usual definition of life.
- Describe the evidence that viruses probably evolved from fragments of cellular nucleic acids.
- Define and describe mobile genetic elements.
- Explain how viral infections in animals cause disease.
- Describe the best current medical defenses against viruses. Explain how AZT helps to fight HIV infections.
- Describe the mechanisms by which new viral diseases emerge.
- Distinguish between the horizontal and vertical routes of viral transmission in plants.
- Describe viroids and prions.
- Explain how a non-replicating protein can act as a transmissible pathogen.
The Genetics of Bacteria
- Describe the structure of a bacterial chromosome.
- Compare the sources of genetic variation in bacteria and humans.
- Compare the processes of transformation, transduction, and conjugation.
- Distinguish between generalized and specialized transduction.
- Define an episome. Explain why a plasmid can be an episome.
- Explain how the F plasmid controls conjugation in bacteria.
- Describe the significance of R plasmids. Explain how the widespread use of antibiotics contributes to R plasmid-related disease.
- Explain how transposable elements may cause recombination of bacterial DNA.
- Distinguish between an insertion sequence and a transposon.
- Describe the role of transposase in the process of transposition.
- Briefly describe two main strategies that cells use to control metabolism.
- Explain the adaptive advantage of genes grouped into an operon.
- Using the trp operon as an example, explain the concept of an operon and the function of the operator, repressor, and corepressor.
- Distinguish between structural and regulatory genes.
- Describe how the lac operon functions and explain the role of the inducer, allolactose.
- Explain how repressible and inducible enzymes differ and how those differences reflect differences in the pathways they control.
- Distinguish between positive and negative control and give examples of each from the lac operon.
- Explain how cyclic AMP and catabolite activator protein are affected by glucose concentration.